SARILUMAB

PRONUNCIATION sar il’ ue mab

THERAPEUTIC CLAIM Treatment of rheumatoid arthritis and
ankylosing spondylitis

CHEMICAL NAMES

1. Immunoglobulin G1, anti-(human interleukin 6 receptor α) (human REGN88 heavy
chain), disulfide with human REGN88 light chain, dimer

2. Immunoglobulin G1, anti-(human interleukin-6 receptor subunit alpha (IL-6RA,
membrane glycoprotein 80, CD126)); human monoclonal RGN88 γ1 heavy chain (219-
214′)-disulfide with human monoclonal RGN88 κ light chain dimer (225-225”:228-
228”)-bisdisulfide

MOLECULAR FORMULA C6388H9918N1718O1998S44

MOLECULAR WEIGHT 144.13 kDa

SPONSOR Regeneron Pharmaceuticals, Inc.

CODE DESIGNATION REGN88, SAR153191

CAS REGISTRY NUMBER 1189541-98-7

sarilumab

Sarilumab (REGN88/SAR153191) is a fully-human monoclonal antibody directed against the IL-6 receptor (IL-6R).  Sarilumab is a subcutaneously delivered inhibitor of IL-6 signaling, which binds with high affinity to the IL-6 receptor.  It blocks the binding of IL-6 to its receptor and interrupts the resultant cytokine-mediated inflammatory signaling.

Sanofi and Regeneron’s investigational rheumatoid arthritis drug sarilumab has succeeded in a late-stage trial.

The year-long Phase III study enrolled 1,200 patients with active, moderate-to-severe RA who were inadequate responders to methotrexate. Patients were randomised to one of three subcutaneous treatment groups, all in combination with MTX and dosed every other week – sarilumab 200mg, 150mg or placebo.http://www.pharmatimes.com/Article/13-11-22/Late-stage_success_for_Sanofi_Regeneron_RA_drug.aspx

Sarilumab is a human monoclonal antibody against the interleukin-6 receptor.

Regeneron and Sanofi are currently co-developing the drug for the treatment of rheumatoid arthritis, for which it is in phase III trials. Development inankylosing spondylitis has been suspended after the drug failed to show clinical benefit over methotrexate in a phase II trial.^[1][2]

On May 15th, 2013, both companies announced that 2 new trials were starting (COMPARE and ASCERTAIN) and the first patients had already been enrolled.^[3]

On November 22nd, 2013, both companies On May 15th, 2013, both companies announced positive phase 3 results for the RA-MOBILITY trial

1.  “Statement On A Nonproprietary Name Adopted By The USAN Council: Sarilumab”. American Medical Association.
2.  http://investor.regeneron.com/releasedetail.cfm?releaseid=590869
3.  http://en.sanofi.com/Images/33027_20130515_sari_en.pdf

fully human monoclonal antibody directed against the interleukin-6 receptor (IL-6R) in combination with methotrexate (MTX) therapy improved disease signs and symptoms as well as physical functionw while inhibiting progression of joint damage in adults with RA who saw little improvement through MTX therapy alone.

Sarilumab met all three primary endpoints of the 52-week SARIL-RA-MOBILITY Phase III trial by demonstrating clinically relevant and statistically significant improvements compared to the placebo group in the two groups treated with the drug candidate. The trial enrolled about 1,200 patients with active, moderate-to-severe rheumatoid arthritis who were inadequate responders to MTX therapy.

Of patients treated with the 200 mg dose of sarilumab plus MTX, 66% saw improvement in signs and symptoms of RA at 24 weeks, as measured by the American College of Rheumatology score of at-least 20% improvement. The percentage dipped to 58% of sarilumab 150 mg dose patients, and 33% of placebo patients.

Sarilumab 200 mg patients showed the least progression of structural damage after 52 weeks, registering a 0.25 change in the modified Van der Heijde total Sharp score. That contrasts with scores of 0.90 in patients taking sarilumab 150 mg, and 2.78 in the placebo group.

In addition, sarilumab 200 mg patients showed improvement in physical function, as measured by change from baseline in the Health Assessment Question-Disability at week 16. However, the companies did not quantify those results in their announcement. Sanofi and Regeneron said additional analyses of efficacy and safety data from SARIL-RA-MOBILITY will be presented “at a future medical conference.”

“We are encouraged by these Phase III results and the impact sarilumab demonstrated on inhibition of progression of structural damage assessed radiographically in this study,” Tanya M. Momtahen, Sanofi’s sarilumab global project head, said in a statement.

Sarilumab—known as SAR153191 and REGN88—blocks the binding of IL-6 to its receptor and interrupts the resultant cytokine-mediated inflammatory signaling characteristic of RA. Sarilumab was developed using Regeneron’s VelocImmune® antibody technology.

The positive results continue what has been mostly strong success in clinical trials for the partners, whose development collaborations include alirocumab (REGN727), dupilumab (REGN668), and enoticumab (REGN421). Alirocumab is a PCSK9 antibody being evaluated for its ability to manage LDL cholesterol, including in people who do not get to their target LDL levels using statin medicines alone. Dupilumab is an antibody to the receptors for interleukin-4 and interleukin-13 under evaluation in atopic dermatitis and eosinophilic asthma. Enoticumab is a fully human monoclonal antibody to delta-like ligand-4 (Dll4) now in Phase I study for advanced malignancies.

On its own, however, Sanofi’s R&D efforts have shown more mixed results, with the pharma giant earlier this month ending development of cancer drug candidate fedratinib (SAR302503) after it was placed on clinical hold by the FDA following reports that some patients in clinical trials developed symptoms consistent with Wernicke’s encephalopathy. Another cancer compound, iniparib, had its development halted earlier this year after a disappointing Phase III trial.

The SCRIP Awards 2013 celebrated achievements in the global biopharma industry last night at the Lancaster, London.

Hosted by Justin Webb, the evening was a fantastic mix of dining, entertainment and awards.

Among the winners were:

• Novartis’s Bexsero, Best New Drug
• Genmab, Biotech Company of the Year
• Regeneron Pharmaceuticals and Sanofi’s Phase IIa study dupilumab in asthma, Clinical Advance of the Year

You can view the full roll of honour by clicking on the button below.

It was a great night and we would like to thank all those who entered and attended this year’s awards.

Finally congratulations to our winners and a huge thanks to our sponsors for helping us make it such a fantastic success.

Don’t forget to check our website in the next couple of days for all the pictures from the night.

2013 Winners

Best Company in an Emerging Market - Sponsored by Clinigen Group

• Dr Reddy’s Laboratories – India

Best Technological Development in Clinical Trials

• Quintiles’s Infosario Safety

Best Partnership Alliance

• AstraZeneca with Bristol-Myers Squibb and Amylin in diabetes

Financing Deal of the Year

• Mesoblast’s equity financing of Aus$170m

Best Advance in an Emerging Market

• Novartis’s Jian Kang Kuai Che Healthcare Project in China

Clinical Advance of the Year - Sponsored by Quintiles

• Regeneron Pharmaceuticals and Sanofi’s Phase IIa study dupilumab in in asthma

Licensing Deal of the Year - Sponsored by Hume Brophy

• AstraZeneca and Horizon Discovery for the development and commercialization of the HD-001 kinase target program for multiple cancer types

Executive of the Year

• Roch Doliveux, chairman and chief executive officer of UCB

Biotech Company of the Year

• Genmab

Best Contract Research Organization

• Quintiles

Management Team of the Year

• Regeneron Pharmaceuticals’ CEO Leonard S Schleifer and CSO George D Yancopoulos

Best New Drug - Sponsored by INC Research

• Novartis’ Bexsero (meningococcal group B vaccine)

Pharma Company of the Year - Sponsored by ICON

• Astellas

Lifetime Achievement Award

• Prof Dr Désiré Collen

   

…….read about bexero at

http://newdrugapprovals.wordpress.com/2013/02/02/novartis-gets-european-approval-for-first-meningitis-b-vaccine/

DR ANTHONY MELVIN CRASTO Ph.D

amcrasto@gmail.com

The U.S. Food and Drug Administration said on Friday it has expanded the approved use of the cancer drug Nexavar to include late-stage differentiated thyroid cancer.

Differentiated thyroid cancer is the most common type of thyroid cancer, the FDA said. The National Cancer Institute estimates that 60,220 people in the United States will be diagnosed with it and 1,850 will die from the disease in 2013.

The drug, made by Germany’s Bayer AG and Onyx Pharmaceuticals, is already approved to treat advanced kidney cancer and liver cancer that cannot be surgically removed. Onyx was acquired by Amgen Inc earlier this year.

READ ABOUT SORAFENIB IN MY EARLIER BLOGPOST

http://newdrugapprovals.wordpress.com/2013/07/16/nexavar-sorafenib/

Otsuka and Lundbeck’s Once-Monthly Abilify Maintena(R) (Aripiprazole) Now Approved in Europe for Maintenance Treatment of Schizophrenia in Adult Patients Stabilized with Oral Aripiprazole

do not forget to see my old blog post, contains synthesis

http://newdrugapprovals.wordpress.com/2013/02/07/the-european-medicines-agency-ema-approves-otsukas-aripiprazole-abilify-for-the-treatment-of-moderate-to-severe-manic-episodes-in-bipolar-i-disorder-in-adolescents/

Preventing relapse is critical in the treatment of schizophrenia. Pivotal 
      studies, that supported the EU submission, demonstrate that Abilify 
      Maintena can reduce the risk of relapse relative to placebo and is 
      non-inferior to oral aripiprazole in patients with schizophrenia1,2 

   -- The approval of Abilify Maintena now provides patients with schizophrenia 
      access to a once-monthly formulation with established efficacy together 
      with a tolerability profile that is comparable to that of oral ABILIFY(R) 
      (aripiprazole)2 

   -- At the end of the randomized, double-blind treatment phase in one of the 
      pivotal trials, 93 percent of patients reported being extremely, very or 
      somewhat satisfied with Abilify Maintena treatment3 

   -- Abilify Maintena is the only dopamine D2 partial agonist in a 
      once-monthly, injectable form to receive marketing authorization in 
      Europe for maintenance treatment of schizophrenia 

   -- Abilify Maintena will be the first commercialized product in Europe from 
      the global alliance between Otsuka and Lundbeck which is focused on 
      developing Central Nervous System (CNS) therapies worldwide 
TOKYO & COPENHAGEN, Denmark--(BUSINESS WIRE)--November 21, 2013--

Otsuka Pharmaceutical Co., Ltd. (Otsuka) and H. Lundbeck A/S (Lundbeck) today announced marketing authorization approval from the European Commission for Abilify Maintena (aripiprazole), an intramuscular (IM) once-monthly injectable formulation for maintenance treatment of schizophrenia in adult patients stabilized with oral aripiprazole.

Abilify Maintena reduces the risk of relapse relative to placebo over the long-term and provides effective treatment of schizophrenia.(1,2) It has a tolerability profile similar to oral aripiprazole(1) , and demonstrated statistically significant benefits on patients’ personal and social functioning as compared to placebo.(1,4) 93 percent of patients treated with Abilify Maintena were extremely, very or somewhat satisfied with their treatment at the end of the double-blind treatment phase.(4)

“We strongly believe the schizophrenia community will welcome the availability of Abilify Maintena to help improve outcomes for patients living with schizophrenia. As a company, our focus is to develop treatments to help protect against relapse and preserve brain function,” said Ole Vahlgren, CEO & President, Otsuka Europe. “We must partner with health care professionals and caregivers to help patients get the best treatments that focus on reducing the risk of relapse.”

“Studies have shown that the early use of long-acting injectables can prevent a person with schizophrenia from experiencing a relapse,”(5) said Ole Chrintz, SVP International Markets & Europe, Lundbeck. “Efficacy is important, but a treatment for a chronic condition such as schizophrenia also needs to be well tolerated so patients will stay on it over the long-term. We believe Abilify Maintena meets this need.”(1,2,3)

About the Studies

The efficacy of Abilify Maintena was demonstrated in two double-blind, Phase III, randomized trials. The safety profile for Abilify Maintena was demonstrated to be similar to that of oral ABILIFY. The most frequently observed adverse drug reactions (ADRs) reported in >=5 percent of patients in two double-blind controlled clinical trials of Abilify Maintena were weight increases (9.0 percent), akathisia (7.9 percent), insomnia (5.8 percent), and injection site pain (5.1 percent).(1,2)

About Abilify Maintena

Abilify Maintena is the only dopamine D2 partial agonist in once-monthly, injectable form to receive marketing authorization for maintenance treatment in schizophrenia. Physicians now have an alternative treatment option, with a tolerability profile comparable to the well-established oral ABILIFY, to address the on-going need to reduce the risk of relapse in patients with schizophrenia.

The European label states that Abilify Maintena is a powder and solvent for prolonged-release suspension for intra-muscular (IM) injection. It is a once-monthly formulation of aripiprazole in a sterile lyophilized powder that is reconstituted with sterile water. Abilify Maintena is indicated for maintenance treatment of schizophrenia in adult patients stabilized with oral aripiprazole.

After the first injection, treatment with 10 mg to 20 mg oral aripiprazole should be continued for 14 consecutive days to maintain therapeutic aripiprazole concentrations during initiation of therapy.

About Schizophrenia and Disease Relapse

Schizophrenia is a disease characterized by a distortion in the process of thinking and of emotional responsiveness. It most commonly manifests as hallucinations, paranoid or bizarre delusions, or disorganized speech and thinking, and is accompanied by significant social or occupational dysfunction. Onset of symptoms typically occurs in young adulthood, and the condition is chronic, often requiring lifelong treatment to mitigate symptoms.

Relapse of schizophrenia refers to an exacerbation or acute psychotic break that is characterised primarily by the emergence of positive symptoms such as hallucinations, delusions and disordered thinking.(6)

Relapse can occur when a patient no longer responds to antipsychotic medication, does not take the medication as prescribed, or stops taking their medication altogether. There are many reasons patients stop taking their medication, including poor insight about their illness, side effects from current treatments, complicated medication regimen or lack of support from family.(7) Abilify Maintena is able to significantly reduce the risk of relapse in patients with schizophrenia.(1)

It has been estimated that schizophrenia affects approximately one percent of the adult population in the U.S. and Europe, and approximately 24 million people worldwide.(8,9) In Europe there are approximately 4.4 million adults with schizophrenia,(10) prevalent equally in both genders.(11,12) While there is no cure for the disease, symptoms and risk of relapse can be managed in most patients with appropriate antipsychotic treatment. However, when the disease is not managed, patients are at increased risk of disease relapse, which can cause the re-emergence or worsening of psychotic symptoms.(13)

Schizophrenia places a significant burden on society. It is regarded among the most financially costly illnesses and is according to the World Health Organization (WHO), the 8(th) leading cause of DALYs (lost healthy years) worldwide among patients between the age of 15-44.(11) With 50 percent of patients not receiving appropriate care and 80 percent of patients relapsing within the first 5 years,(14) there is a significant unmet need to be addressed in schizophrenia.

About the Lundbeck and Otsuka Global Alliance

Lundbeck and Otsuka established a global alliance in November 2011 to bring to bear their considerable experience and resources in the CNS area to introduce next-generation treatments for conditions such as schizophrenia, depression, Alzheimer’s disease and alcohol dependency.

About Otsuka Pharmaceutical Co., Ltd.

Otsuka Pharmaceutical Co., Ltd. is a global healthcare company with the corporate philosophy: ‘Otsuka-people creating new products for better health worldwide.’ Otsuka researches, develops, manufactures and markets innovative and original products, with a focus on pharmaceutical products for the treatment of diseases and nutraceutical products for the maintenance of everyday health.

In pharmaceuticals, Otsuka is a leading firm in the challenging area of mental health and also has research programs for several under-addressed diseases including tuberculosis, a significant global public health issue. These commitments illustrate more powerfully than words how Otsuka is a “big venture” company at heart, applying a youthful spirit of creativity in everything it does.

Otsuka is a wholly owned subsidiary of Otsuka Holdings Co., Ltd., the holding company for the Otsuka Group. The chairman Akihiko Otsuka is the third generation of Otsuka family members to lead the business, whose origins date from 1921. The Otsuka Group employs approximately 42,000 people globally and its products are available in more than 80 countries worldwide. Consolidated sales were approximately EUR10 billion or USD 13 billion for fiscal year 2012 (4/1/2012-3/31/2013). Otsuka Pharmaceutical welcomes you to visit its global website at https://www.otsuka.co.jp/en/

About H. Lundbeck A/S

Lundbeck is a global pharmaceutical company highly committed to improving the quality of life of people living with brain diseases. For this purpose, Lundbeck is engaged in the entire value chain throughout research, development, production, marketing and sales of pharmaceuticals across the world. The company’s products are targeted at disorders such as depression and anxiety, psychotic disorders, epilepsy, Huntington’s, Alzheimer’s and Parkinson’s diseases. Lundbeck’s pipeline consists of several mid- to late-stage development programmes.

Lundbeck employs more than 5,800 people worldwide, 2,000 of whom are based in Denmark. We have research in 57 countries and our products are registered in more than 100 countries. We have research centers in Denmark, China and the United States and production facilities in Italy, France, Mexico, China and Denmark. Lundbeck generated revenue of approximately DKK 15 billion in 2012. For additional information, we encourage you to visit our corporate site http://www.lundbeck.com.

 

REFERENCES: 
1.   Kane, JM et al. Aripiprazole intramuscular depot as maintenance treatment in 
     patients with schizophrenia: a 52-week, multicenter, randomized, 
     double-blind, placebo-controlled study. J Clin Psychiatry 2012;73(5):617-62 
2.   Fleischhacker WW, Sanchez R, Perry PP, et al. Aripiprazole once-monthly for 
     the treatment of schizophrenia: a double-blind, randomized, non-inferiority 
     study vs. oral aripiprazole. Annual Meeting of the American Psychiatric 
     Association, 18--22 May, 2013 (poster). 
3.   Sanchez R, et al. Patient-reported Outcomes with 
     Aripiprazole-Intramuscular-Depot for Long-term Maintenance Treatment in 
     Schiziphrenia. NR6-42 2012 (poster) 
4.   Carson WH, Perry P, Sanchez R, et al. Effects of a Once-Monthly Formulation 
     of Aripiprazole on Secondary Efficacy Outcomes in Maintenance Treatment of 
     Schizophrenia. Institute on Psychiatric Services meeting, October 4--7, 2012 
     (Poster) 
5.   Long-acting injectable antipsychotics in the treatment of schizophrenia: 
     their role in relapse prevention. Agid O, et al. Expert Opin. Pharmacother. 
     (2010) 11(14):2301-2317 
6.   Ayuso-Gutierrez JL, del Rio Vega JM. Factors influencing relapse in the 
     long-term course of schizophrenia. Schizophr Res. 1997; 28(2-3): 199-206 
7.   Baloush-Kleinman V, et al. Adherence to antipsychotic drug treatment in 
     early-episode schizophrenia: a six-month naturalistic follow-up study. 
     Schizophr Res. 2011;130(1-3):176-81. 
8.   National Institute of Mental Health (NIMH). Health Topics: Statistics. 
     Available at http://www.nimh.nih.gov/statistics/1SCHIZ.shtml. Accessed 
     October 22, 2013 
9.   World Health Organization (WHO). Schizophrenia Fact Sheet. 2010. Available 
     at: http://www.who.int/mental_health/management/schizophrenia/en/. Accessed 
     October 22, 2013. 
10.  World Health Organization (WHO) The global burden of disease:2004 update 
     (2008) 
11.  National Institute of Mental Health (NIMH). The Numbers Count: Mental 
     Disorders in America. 2010. Available at 

http://www.nimh.nih.gov/health/publications/the-numbers-count-mental-disorde

     rs-in-America/index.shtml#Schizophrenia. Accessed October 22, 2013 
12.  Regier DA, et al. The de facto US mental and addictive disorders service 
     system. Epidemiologic catchment area prospective 1-year prevalence rates of 
     disorders and services. Arch Gen Psychiatry. 1993;50(2):85-94. 
13.  American Psychiatric Association. Practice guideline for the treatment of 
     patients with schizophrenia. Second edition. 2004. Available at 

http://psychiatryonline.org/content.aspx?bookid=28&sectionid=1665359.

     Accessed October 28, 2013 
14.  Robinson D, et al. Predictors of relapse following response from a first 
     episode of schizophrenia or schizoaffective disorder. Arch Gen Psychiatry. 
     1999;56(3):241-247



read my earlier blog post
http://newdrugapprovals.wordpress.com/2013/02/07/the-european-medicines-agency-ema-approves-otsukas-aripiprazole-abilify-for-the-treatment-of-moderate-to-severe-manic-episodes-in-bipolar-i-disorder-in-adolescents/

simeprevir

November 22, 2013 — The U.S. Food and Drug Administration today approved Olysio (simeprevir), a new therapy to treat chronic hepatitis C virus infection.

OLYSIO™ is the first once-daily protease inhibitor approved for the treatment of chronic hepatitis C in a combination antiviral regimen for adults with compensated liver disease

Hepatitis C is a viral disease that causes inflammation of the liver that can lead to diminished liver function or liver failure. Most people infected with the hepatitis C virus have no symptoms of the disease until liver damage becomes apparent, which may take several years. Most of these people then go on to develop chronic hepatitis C. Some will also develop scarring and poor liver function (cirrhosis) over many years, which can lead to complications such as bleeding, jaundice (yellowish eyes or skin), fluid accumulation in the abdomen, infections or liver cancer. According to the Centers for Disease Control and Prevention, about 3.2 million Americans are infected with the hepatitis C virus

Hepatitis C virus (HCV) infections affect approximately 3 percent of the worldwide population and often lead to cirrhosis and hepatocellular carcinoma. The standard therapy of pegylated- interferon and ribavirin induces serious side effects and provides viral eradication in less than 50% of patients. Combination therapy of HCV including ribavirin and interferonare currently is the approved therapy for HCV. Unfortunately, such combination therapy also produces side effects and is often poorly tolerated, resulting in major clinical challenges in a significant proportion of patients. Numerous direct acting agents (DAAs) have been or are being developed for treatment of HCV, such as telaprevir and boceprevir (both received MA approved in 2011 for use with interferon and ribavirin based therapy), however direct acting agents are linked to increased toxicity of treatment, the emergence of resistance, and to date do not provide a standard of care which is interferon free. The combination of direct acting agents can also result in drug-drug interactions. To date, no HCV therapy has been approved which is interferon free. There is therefore a need for new combination therapies which have reduced side effects, and interferon free, have a reduced emergence of resistance, reduced treatment periods and/or and enhanced cure rates.

Simeprevir (formerly TMC435) is an experimental drug candidate for the treatment of hepatitis C. It is being developed byMedivir and Johnson & Johnson‘s pharmaceutical division Janssen Pharmaceutica and is currently in Phase III clinical trials.^[1]

Simeprevir is a hepatitis C virus protease inhibitor.^[2]

Simeprevir is being tested in combination regimens with pegylated interferon alfa-2a and ribavirin,^[3] and in interferon-free regimens with other direct-acting antiviral agents including daclatasvir^[4] and sofosbuvir ^[5]

“Hepatitis C is a complex disease and Janssen is committed to working with the HCV community, caregivers, and health care systems to address this global epidemic,” said Gaston Picchio, Hepatitis Disease Area Leader, Janssen Research & Development. “We are pleased that the FDA has granted simeprevir Priority Review, as it is a significant step forward in making this therapy available to physicians and their hepatitis C patients.”

,,,,,,,,,,,,,

GlaxoSmithKline (GSK) has received approval from the US Food and Drug Administration (FDA) for the first adjuvanted vaccine to prevent H5N1 influenza, also known as bird flu.

GSK obtains FDA approval for bird flu vaccine http://www.pharmaceutical-technology.com/news/newsgsk-obtains-fda-approval-bird-flu-vaccine?WT.mc_id=DN_News

GlaxoSmithKline (GSK) has received approval from the US Food and Drug Administration (FDA) for the first adjuvanted vaccine to prevent H5N1 influenza, also known as bird flu.

The FDA cleared the pandemic Influenza A (H5N1) virus monovalent vaccine, adjuvanted (also referred to as Q-Pan H5N1 influenza vaccine), for use in people aged 18 and older who are at increased risk of exposure to the virus.

The vaccine is composed of monovalent, inactivated, split A/H5N1 influenza virus antigen and GSK’s AS03 adjuvant.

The company said that in clinical studies, the adjuvanted formulation stimulated the required immune response while using a smaller amount of antigen as compared with a formulation without adjuvant.

GT-111
VB-111

GT-111 is a gene therapy product candidate in early clinical development for the treatment of advanced differentiated thyroid cancer, for the treatment of relapsed glioblastoma multiform and for the treatment of ovarian cancer.

patents, VBL Therapeutics

WO 2011083466, WO-2011083464, WO-2012052878

VBL Therapeutics announced today that the U.S. Food and Drug Administration (FDA) has granted Fast Track designation to its lead oncology drug VB-111, for prolongation of survival in patients with recurrent glioblastoma multiforme (rGBM).

Read more…http://www.dddmag.com/news/2013/11/vbls-cancer-drug-gets-fast-tracked?et_cid=3625663&et_rid=523035093&type=cta

VB-111 – highly targeted anti-angiogenic agent for the specific inhibition of tumor vascular growth

VB-111 is the first highly targeted anti-angiogenic agent for the specific inhibition of tumor vascular growth to use VTS™™, our proprietary platform technology, for cancer therapy. VB-111 is an IV-administered anti angiogenic agent that works in a manner akin to a “biological knife” to destroy tumor vasculature, thus cutting off blood vessels feeding the tumor.

Preclinical Insights

VB-111 has shown significant promise as a targeted cancer treatment with the potential to work synergistically in combination with conventional chemotherapy treatments to provide an effective treatment regimen for cancer patients. Pharmacological and toxicology studies of VB-111 have showed tissue specificity for the tumor tissue, no significant damage to normal non-cancerous tissues or to the normal vasculatures in the body and more than 90 percent tumor burden reduction in a metastatic lung cancer model with only one injection. Similar efficacy was shown in other tumor models.

Completed Clinical Trials

Phase 1 Clinical Trial – in a Phase 1 “all comers” dose escalation study in 33 patients with advanced metastatic cancer, therapeutic doses of VB-111 demonstrated antitumor activity and was found to be safe and well tolerated with no effect on liver function or major changes in complete blood count. Findings have been presented at the American Association of Cancer Research (AACR) and the American Society of Clinical Oncology (ASCO) annual meetings.

Teva Announces Additional Regulatory Exclusivity for TREANDA® (Bendamustine HCI) for Injection

Orphan Designation combined with pediatric extension provides regulatory exclusivity through April 2016 for indolent B-cell non-Hodgkin lymphoma indication

JERUSALEM, November 27, 2013 –(BUSINESS WIRE)–Teva Pharmaceutical Industries Ltd. (NYSE: TEVA) today announced that the U.S. Food and Drug Administration (FDA) has granted orphan drug exclusivity for TREANDA through October 2015 for indolent B-cell non-Hodgkin lymphoma (iNHL) that has progressed during or within six months of treatment with rituximab or a rituximab-containing regimen.http://www.pharmalive.com/teva-announces-additional-regulatory-exclusivity-for-treanda

read my old post, contains synthesis

http://newdrugapprovals.wordpress.com/2013/09/19/fda-oks-tevas-injectable-treanda/

THERAPEUTIC CLAIM Oral phosphate binder, treatement of elevated
phosphate levels in patients undergoing dialysis
CHEMICAL DESCRIPTIONS
1. Ferric hydroxide oxide
2. Mixture of iron(III) oxyhydroxide, sucrose, starches
3. Polynuclear iron(III) oxyhydroxide stabilized with sucrose and starches
structure
O =Fe -OH
MOLECULAR FORMULA FeHO2•xC12H22O11•y(C6H10O5)n

SPONSOR Vifor (International) Inc.
CODE DESIGNATIONS PA21
CAS REGISTRY NUMBER 12134-57-5

sucroferric oxyhydroxide

Sucroferric oxyhydroxide nonproprietary drug name

1. February 27, 2013. N13/36. STATEMENT ON A NONPROPRIETARY NAME ADOPTED BY THE USAN COUNCIL. USAN (ZZ-19). SUCROFERRIC …

The US Food and Drug Administration has given the green light to Vifor Fresenius Medical Care Renal Pharma’s hyperphosphatemia drug Velphoro.

The approval for Velphoro (sucroferric oxyhydroxide), formerly known as PA21, is based on Phase III data demonstrated that the drug successfully controls the accumulation of phosphorus in the blood with the advantage of a much lower pill burden than the current standard of care in patients with chronic kidney disease on dialysis, namely Sanofi’s Renvela (sevelamer carbonate). read this at

http://www.pharmatimes.com/Article/13-11-28/FDA_okays_Vifor_Fresenius_phosphate_binder_Velphoro.aspx

Velphoro (PA21) receives US FDA approval for the treatment of hyperphosphatemia in Chronic Kidney Disease Patients on dialysis
Velphoro (sucroferric oxyhydroxide) has received US Food and Drug Administration (FDA) approval for the control of serum phosphorus levels in patients with Chronic Kidney Disease (CKD) on dialysis. Velphoro will be launched in the US by Fresenius Medical Care North America in 2014.

Velphoro (previously known as PA21) is an iron-based, calcium-free, chewable phosphate binder. US approval was based on a pivotal Phase III study, which met its primary and secondary endpoints. The study demonstrated that Velphoro^® successfully controls hyperphosphatemia with fewer pills than sevelamer carbonate, the current standard of care in patients with CKD on dialysis. The average daily dose to control hyperphosphatemia was 3.3 pills per day after 52 weeks.

Velphoro was developed by Vifor Pharma. In 2011, all rights were transferred to Vifor Fresenius Medical Care Renal Pharma, a common company of Galenica and Fresenius Medical Care. In the US, Velphorowill be marketed by Fresenius Medical Care North America, a company with a strong marketing and sales organization, and expertise in dialysis care. The active ingredient of Velphoro is produced by Vifor Pharma in Switzerland.

Hyperphosphatemia, an abnormal elevation of phosphorus levels in the blood, is a common and serious condition in CKD patients on dialysis. Most dialysis patients are treated with phosphate binders. However, despite the availability of a number of different phosphate binders, up to 50% of patients depending on the region are still unable to achieve and maintain their target serum phosphorus levels. In some patients, noncompliance due to the high pill burden and poor tolerability appear to be key factors in the lack of control of serum phosphorus levels. On average, dialysis patients take approximately 19 pills per day with phosphate binders comprising approximately 50% of the total daily pill burden. The recommended starting dose of Velphoro is 3 tablets per day (1 tablet per meal).

Full results from the pivotal Phase III study involving more than 1,000 patients were presented at both the 50^th ERA-EDTA (European Renal Association European Dialysis and Transplant Association) Congress in Istanbul, Turkey, in May 2013, and the American Society of Nephrology (ASN) Kidney Week in Atlanta, Georgia, in November 2013. Velphorowas shown to be a potent phosphate binder, with lower pill burden and a good safety profile.

Based on these data, Vifor Fresenius Medical Care Renal Pharma believes that Velphoro offers a new and effective therapeutic option for the control of serum phosphorus levels in patients with chronic kidney disease on dialysis.
The regulatory processes in Europe, Switzerland and Singapore are ongoing and decisions are expected in the first half 2014. Further submissions for approval are being prepared.

ZAFIRLIKAST 

cyclopentyl 3-{2-methoxy-4-[(o-tolylsulfonyl)carbamoyl]benzyl}-1-methyl-1H-indol-5-ylcarbamate

107753-78-6

Matassa, V.G. et al, J. Med. Chem., v. 33, 1781 (1990);

U. S. Patent No. 4,859,692;

U. S. Patent No. 5,993,859;

Zafirlukast is an oral leukotriene receptor antagonist (LTRA) for the maintenance treatment of asthma, often used in conjunction with an inhaled steroid and/or long-acting bronchodilator. It is available as a tablet and is usually dosed twice daily. Another leukotriene receptor antagonist is montelukast (Singulair), taken once daily. Zileuton (Zyflo), also used in the treatment of asthma via its inhibition of 5-lipoxygenase, is taken four times per day.

Zafirlukast blocks the action of the cysteinyl leukotrienes on the CysLT1 receptors, thus reducing constriction of the airways, build-up of mucus in the lungs andinflammation of the breathing passages.

Zafirlukast is marketed by Astra Zeneca with the brand names Accolate, Accoleit, and Vanticon. It was the first LTRA to be marketed in the USA and is now approved in over 60 countries, including the UK, Japan, Taiwan, Italy, Spain, Canada, Brazil, China and Turkey

Healthy young men who received a single oral 40 mg dose attained peak plasma zafirlukast concentrations that averaged 607 μg/L at 3.4 hours. The elimination half-life ranged from 12 to 20 hours. In another study involving a 20 mg single oral dose in healthy men, the elimination half-life averaged 5.6 hours.^[1][2]

A letter was submitted to the FDA by Zeneca Pharmaceuticals on July 22, 1997, notifying them of a change in product labeling that includes the following potential reaction in patients undergoing a dosage reduction of oral steroids who are currently taking zafirlukast:

PRECAUTIONS-Eosinophilic Conditions: The reduction of the oral steroid dose, in some patients on ACCOLATE therapy, has been followed in rare cases by the occurrence of eosinophilia, vasculitic rash, worsening pulmonary symptoms, cardiac complications, and/or neuropathy sometimes presenting as Churg–Strauss syndrome, a systemic eosinophilic vasculitis. Although a causal relationship with ACCOLATE has not been established, caution is required when oral steroid reduction is being considered.¹

Zafirlukast is a synthetic, selective peptide leukotriene receptor antagonist (LTRA), with the chemical name 4(5-cyclopentyloxy-carbonylamino-1-methyl-indol-3ylmethyl)-3-methoxy-N-o-tolylsulfonylbenzamide. The molecular weight of zafirlukast is 575.7 and the structural formula is:

The empirical formula is: C₃₁H₃₃N₃O₆S

Zafirlukast, a fine white to pale yellow amorphous powder, is practically insoluble in water. It is slightly soluble in methanol and freely soluble in tetrahydrofuran, dimethylsulfoxide, and acetone.

• Zafirlukast (U.S. National Library of Medicine)
• Zafirlukast (patient information)

Zafirlukast, cyclopentyl 3 – [2-methoxy-4- [(o-tolylsulfonyl)carbamoyl]- benzyl]-l-methyIindole-5-carbamate, having the formula:

is a first anti-asthmatic leukotriene antagonist (Matassa, V.G. et al, J. Med. Chem., v. 33, 1781 ^‘(1990); U. S. Patent No. 4,859,692 and The Merck Index, 12th Edition, 10241). Methods for the preparation of Zafirlukast are described in J. Med. Chem., v. 33, 1781 (1990), U. S. Patent 4,859,692 and U.S. Patent 5,993,859 starting from methyl 3-methoxy-4-(l-methyl-5-nitroindol-3-ylmethyl)benzoate [la]

Alkyl (l-alkylindol-3-ylmethyl)benzoates of formula [lb] are useful as chemical intermediates in the pharmaceutical industry.

These compounds may be obtained by a process described in J. Med. Chem., v. 33, 1781 (1990) and U. S. Patent 4,859,692. This process comprises the steps of:

(a) reacting an alkyl (halomethyl)benzoate of formula [2] with an equivalent amount of an indole of formula [3]

in the presence of an equivalent quantity of silver(I) oxide,

(b) isolating the alkyl (indol-3-ylmethyl)benzoates of formula [4] from the reaction mixture obtained in step (a) above,

(c) reacting the compound [4] with an alkylating agent of formula [6],

The above process has serious disadvantages in the isolation of the product [4] in step (b) which is due to the fact that alkylation of indole, that is unsubstituted at positions 1-, 2- and 3-, at the 3-position, is accompanied by the undesired process of poly alkylation, to form polysubstituted indoles of formula [7] and/or formula [8] :

while at the same time some quantity of the starting unreacted indole remains in the reaction mixture. Most common methods for the separation of alkyl (indol-3-ylmethyl)benzoate of formula [4] from by-products of polyalkylation and starting unreacted indole, which are all covalent compounds with similar physical properties, include column chromatography that is an unpractical method for industrial scale applications.

Formula (I) compound for the synthesis of an important intermediate of zafirlukast.Reported in the patent EP199543 synthesized compound (I) of the conventional method, the following formula:

(A) (I)

 In this method, Intermediate A and 5 – nitro-indole silver oxide in the presence of a catalyst, for docking composite formula (I) compound. Reported only 45% of the reaction yield, the reaction is difficult to complete the reaction and post-treatment using chromatographic methods, resulting in product purification more difficult. And the use of more expensive silver oxide catalysts, high cost.

 W00246153 reported a catalyst for the above reaction to zinc bromide, Compound (I), after treatment of the compound (I) with sodium hydroxide hydrolysis of the intermediate (B), separating the product and raw materials purification products.

 

The method reported in the literature a yield of 60%, but the actual operation is repeated only about 30% yield, and the operation is complicated, cumbersome and costly.

zaafirlukast is a selective and competitive receptor antagonist of leukotriene D4 and E4 (LTD4 and LTE4), components of slow-reacting substance of anaphylaxis (SRSA). Cysteinyl leukotriene production and receptor occupation have been correlated with the pathophysiology of asthma, including airway edema, smooth muscle constriction, and altered cellular activity associated with the inflammatory process, which contribute to the signs and symptoms of asthma.

The cysteinyl leukotrienes (LTC₄ LTD₄, LTE4) are the products of arachidonic acid metabolism and are various cells, including mast cells and eosinophills, these eicosinoids bind to cysteinyl leukotriene (CysLT) receptors. The CysLT type-1 (CysLT₁) receptor is found in human airway and other pro-inflammatory cells. CysLTs have been correlated with the pathophysiology of asthma.

Zafirlukast is a synthetic, selective peptide leukotriene receptor antagonist (LTRA), useful for the treatment of asthma and is commercially available in products sold under the brand name ACCOLATE™ as 10 and 20 mg tablets for oral administration. ACCOLATE™ is indicated for the prophylaxis and treatment of asthma in adults and children 5 years of age and older.

ACCOLATE™ film coated tablets contain amorphous zafirlukast as the active ingredient and the excipients croscarmellose sodium, lactose, magnesium stearate, microcrystalline cellulose, povidone, hypromellose, and titanium dioxide.

The greatest prevalence of asthma is in preschool children; however, the clinical utility of asthma therapy for this age group is limited by a narrow therapeutic index, long-term tolerability, and frequency and/or difficulty of administration. Asthma treatment requires an immediate perceivable effect. Inhalation therapy is a very common therapy prescribed for young children; inhalation therapy has the disadvantage of high dose variability.

Process for the preparation of zafirlukast
US 20040186300 A1

Argatroban
Molecular Formula: C23H36N6O5S
Formula Weight: 508.63
CAS No.: 74863-84-6 

(2R,4R)-1-[(2S)-5-(diaminomethylideneamino)-2-
[[(3R)-3-methyl-1,2,3,4-tetrahydroquinolin-8-yl]
sulfonylamino]pentanoyl]-4-methyl-piperidine-2-
carboxylic acid

PATENT

US 7,589,106, 7,687,516, EP 0008746; US 4258192, US 4201863

Argatroban is an anticoagulant that is a small molecule direct thrombin inhibitor.^[1] In 2000, argatroban was licensed by the Food and Drug Administration (FDA) for prophylaxis or treatment of thrombosis in patients with heparin-induced thrombocytopenia (HIT). In 2002, it was approved for use during percutaneous coronary interventions in patients who have HIT or are at risk for developing it. In 2012, it was approved by the MHRA in the UK for anticoagulation in patients with Heparin-Induced Thrombocytopenia Type II (HIT) who require parenteral antithrombotic therapy.^[2]

Argatroban is given intravenously and drug plasma concentrations reach steady state in 1-3 hours.^[3] Argatroban is metabolized in the liver and has a half-life of about 50 minutes. It is monitored by PTT. Because of its hepatic metabolism, it may be used in patients with renal dysfunction. (This is in contrast to lepirudin, a direct thrombin inhibitor that is primarily renally cleared).

Argatroban is used as an anticoagulant in individuals with thrombosis and heparin induced thrombocytopenia. Often these individuals require long term anticoagulation. If warfarin is chosen as the long term anticoagulant, this poses particular challenges due to the falsely elevated prothrombin time and INR caused by argatroban. The combination of argatroban and warfarin may raise the INR to greater than 5.0 without a significant increased risk of bleeding complications.^[4] One solution to this problem is to measure the chromogenic factor X level. A level < 40-45% typically indicates that the INR will be therapeutic (2-3) when the argatroban is discontinued.

1. Di Nisio M, Middeldorp S, Buller HR. Direct thrombin inhibitors. N Engl J Med2005;353:1028-40. PMID 16148288
2.  http://www.pharmatimes.com/Article/12-07-03/UK_launch_for_Mitsubishi_s_blood_thinner_Exembol.aspx
3.  Dhillon S. Argatroban: A Review of its Use in the Management of Heparin-Induced Thrombocytopenia. Am J Cardiovasc Drugs 2009; 9 (4): 261-82. Link text
4.  Hursting MJ, Lewis BE, Macfarlane DE. (2005). “Transitioning from argatroban to warfarin therapy in patients with heparin-induced thrombocytopenia.”. Clin Appl Thromb Hemost 11 (3): 279–87. doi:10.1177/107602960501100306. PMID 16015413.
5. Bioorg Med Chem Lett2001,11,(15):1989
6. Kikumoto, R., Tamao, Y., Onkubo, K., Tezuka, T., Tonomura, S., Hihikata, A. and Okamoto, S. (Mitsubishi Chem. Inds. Co., Ltd.); EP 8746, US 4258192.
7.  Kikumoto, R., Tamao, Y., Onkubo, K., Tezuka, T., Tonomura, S., Hihikata, A. and Okamoto, S. (Mitsubishi Chem. Inds. Co., Ltd.); US 4201863.

• GlaxoSmithKline’s website on argatroban

……………………………………………………….

Argatroban monohydrate

Argatroban is a synthetic direct thrombin inhibitor and the chemical name is 1-[5-[(aminoiminomethyl) amino]-1-oxo2[[(1,2,3,4-tetrahydro-3-methyl-8-quinolinyl)sulfonyl]amino]pentyl]-4-methyl-2- piperidinecarboxylic acid, monohydrate. Argatroban has 4 asymmetric carbons. One of the asymmetric carbons has an R configuration (stereoisomer Type I) and an S configuration (stereoisomer Type II). Argatroban consists of a mixture of R and S stereoisomers at a ratio of approximately 65:35.

The molecular formula of argatroban is C₂₃H₃₆N₆O₅S•H₂O. Its molecular weight is 526.66 g/mol. cas 141396-28-3

Argipidine, Argatroban monohydrate, GN1600, DK-7419, MDI-805 Acova, Slonnon, Novastan

Mitsubishi Chemical (Originator), Encysive Pharmaceuticals (Licensee), Mitsubishi Pharma (Distributor), Daiichi Pharmaceutical (Codevelopment), GlaxoSmithKline (Codevelopment), Mitsubishi Pharma (Codevelopment), Sanofi-SynthLabo (Codevelopment)

Antithrombocytopenic, CARDIOVASCULAR DRUGS, Cerebrovascular Diseases, Treatment of, HEMATOLOGIC DRUGS, Hematopoiesis Disorders Therapy, Ischemic Stroke, Treatment of, NEUROLOGIC DRUGS, Peripheral Vascular Disease, Treatment of, Stroke, Treatment of, Treatment of Peripheral Obstructive Vascular Disease, Thrombin Inhibitors

Synthesis of argatroban on the method reported in the literature there are two synthetic routes, patent EP8746, US4258192, US4201863, JP8115267 relates to a route is: with 4 – methyl-piperidine as a starting material was prepared first intermediate body (2R, 4R) -4 – methyl-2 – ethyl-piperidine, and the first and a t-BOC protected amino nitro-L-arginine condensation, and then the 3 – methyl – 8 – quinoline sulfonyl chloride condensation after hydrolysis, hydrogenation, hydration be argatroban. This entry route synthesis process complicated procedure to be carried out under the protection of nitrogen, the raw material is highly toxic gas phosgene, the operation more difficult.

US4117127, JP02-212473, EP823430, EP8746, JC S Perk Transl 1981 (5), JP02-212473 relates to an alternative route is: nitro L-arginine prior to the 3 – methyl-8 – subsequent condensation quinoline sulfonyl chloride Intermediate (2R, 4R) -4 – methyl-2 – piperidinecarboxylate condensation, and then after hydrolysis, hydrogenation, hydration be argatroban. This synthetic route despite the relatively simple process method, to obtain raw materials, but this method using reagents such as phosphorus oxychloride, phosphorus trichloride has a pungent odor, easy to absorb moisture in humid air, intense smoke, environmental pollution, greater stimulation of the body’s respiratory tract, can cause eye and skin irritation and burning, and the use of this method, complex operation, low yield, high cost.

Patent CN100586946C Argatroban discloses a method for separating optically active isomeric compounds, the feedstock argatroban mixed solvent of alcohol and water was heated to reflux 5-10 hours, cooled and allowed to stand, and filtered to give White crystalline product, dried, repeated 2-6 times. [0008] Patent CN101033223A discloses a Argatroban is the main by-product (2R, 4R)-l_ [N2-(3_ methyl-8 - quinolinesulfonyl)-L-arginyl] -4 – methyl-2 – carboxylic acid, argatroban, and the byproducts are difficult to isolate, argatroban two diastereomeric isomer 21 (S) and 21 (R) separation of work attracted a lot of research persons. Because both physical and chemical properties are very similar, so separation is very difficult. 1993 Rawson, Thomas E.; VanGorp, Kimmie A.; Yang, Janet so first by high pressure liquid chromatography and column chromatography separation to obtain a single 21 (S) and 21 (R) argatroban [ Journal of Pharmaceutical Sciences vol. 82, No. 6,672]; Thibaudeau Karen et al. reported Protein A chromatographic separation [US6440417]. However, due to the separation of these methods a small amount of low efficiency, so there is no practical value industrialization. 2006 China Tianjin Weijie Technology Co., Ltd. Song Honghai et al. Reported using recrystallization Separation 21 (S) and 21 (R) argatroban way [0 With 951,936 it], so that the mass 21 (5) Aga music classes as possible, but the law of low yield, complicated operation, high cost, and a large amount of a small amount of 21 (S) of 21 (R)-product argatroban, from the viewpoint of industrial production, is still a ideal method. [0009] These methods can be effectively prepared argatroban, but the purity of the desired product is not high, poor color, content is low, affecting the quality of the results of its preparation.

U.S. Pat. No. 4,201,863 (6 May 1980) and EP 8746 (filed on 22 Aug. 1979 with priority based on the application for the cited US patent) describe a class of N2-arylsulphonyl-L-argininamide drugs, with anti-thrombotic activity, and the processes for obtaining them. Of these, the compound 4-methyl-1-[N2-(3-methyl-1,2,3,4-tetrahydro-8-quinolinesulphonyl)-L-arginyl]-2-piperidine carboxylic acid (argatroban, isomers mixture) is described. The described process comprises the synthesis of an intermediate NG-substituted-N2-quinolinesulphonyl-L-argininamide from which the desired compound is obtained by catalyzed hydrogenolysis or acidolysis and catalyzed hydrogenation. The general conditions provided for the hydrogenolysis and hydrogenation reaction are: i) inert solvents (methanol, ethanol, tetrahydrofuran or dioxane); ii) presence of a catalyst (Raney nickel, palladium, platinum, ruthenium, rhodium); iii) hydrogen atmosphere at a pressure between 1 and 100 kg/cm2 and preferably between 5 and 50 kg/cm2; iv) temperature between 0° C. and 200° C. and preferably between 50° C. and 150° C.; v) reaction temperature from 2 hours to 120 hours. The crude product obtained is then purified by trituration or by re-crystallization from diethyl ether-tetrahydrofuran, diethyl ether-methanol or from water-methanol or by chromatography. No example is given of this purification step. In particular, both U.S. Pat. No. 4,210,863 and EP 8746 in example 1(E) describe the preparation of argatroban, isomers mixture. This compound is obtained in amorphous form by hydrogenation of [NG-nitro-N2-(3-methyl-8-quinolinesulphonyl)-L-arginyl]-4-methyl-2-piperidine carboxylic acid in ethanol in the presence of Pd/C with hydrogen pressure of 10 kg/cm2 at 100° C. for 8 hours. The catalyst is removed by filtration of the ethanol solution which is then evaporated without further purification and/or re-crystallization steps. In the US patent at issue as indeed in patent application EP 8746, no mention is made of polymorphic forms of the compounds and, for the obtained compound, the following characteristics are reported: Amorphous solid, I.R. (KBr) (cm−1) 3400; 1620; 1460; 1380; Molecular composition (%): theoretical C 54.31; H 7.13; N 16.52; found (%) C 54.01; H 6.98; N 16.61.

U.S. Pat. No. 4,258,192 (24 Mar. 1981) (continuation-in-part of the aforesaid patent application U.S. Pat. No. 4,201,863) and the same patent application EP 8746 describe the stereoisomers and the preparation thereof, including argatroban used as an active principle in medicaments, i.e. the stereoisomer (2R,4R)-4methyl-[4N2-(3-methyl-1,2,3,4-tetrahydro-8-quinolinesulphonyl)-L-arginyl]-2-piperidine carboxylic acid, with the following characteristics: melting point (m.p.). 188-191° C.; I.R. (KBr) (cm−1) 3400, 1620, 1460, 1380; Molecular composition (%): theoretical C 54.31; H 7.13; N 16.52; found (%) C 54.05; H 6.94; N 16.65. The compound is prepared according to the description given in examples 1(E) in U.S. Pat. No. 4,258,192 and 2(E) and 3 in EP 8746 respectively by hydrogenation of (2R,4R) 1-[NG-nitro-N2-(3-methyl-1,2,3,4-tetrahydro-8-quinolinesulphonyl)-L-arginyl]-2-piperidine carboxylic acid in ethanol in presence of acetic acid catalyzed by Pd/C. After filtering the mass to remove the catalyst, the solvent is evaporated and the residue suspended in chloroform, the solution treated with a saturated sodium bicarbonate solution or 1N sodium hydroxide solution and after washing, the solvent is evaporated. The compound is then re-crystallized from ethanol. Again in this case, no reference is made to the obtainment of monohydrate polymorphic forms.

Said polymorphic forms are described instead in the publication Biochem. Biophys. Res. Comm. 1981, 101, 440-446 in the context of stereoisomer preparation. The monohydrate polymorph of the (2R,4R) stereoisomer is prepared by re-crystallization from ethanol/water and the reported characteristics are: m.p. 176-180° C.; [α]D 27 +76.1° (c 1, 0.2N HCl).

U.S. Pat. No. 5,925,760 (20 Jul. 1999) and EP 0823430 (filed 4 Aug. 1997) subsequently describe a new method for preparing argatroban by means of a new intermediate N2-(3-methyl-8-quinolinesulphonyl)-NG-nitro-L-arginine. In particular the patent makes reference to the preparation of a crystalline monohydrate form of argatroban, referring back to examples (D) and (E) of Japanese patent publication No. (Hei)-2-31055/1990 and generically to an I.R. spectrum identical to that of the commercially available argatroban compound. The relevant example in the cited patent publication is example (E), while example (D) concerns the preparation of (2R,4R)-1-[NG-nitro-N2-(3-methyl-8-quinolinesulphonyl)-L-arginyl]-4-methyl-2-piperidine carboxylic acid. This compound represents the starting compound for argatroban preparation by catalytic reduction in the presence of Pd/C. The crude argatroban obtained is then purified by extraction with chloroform, treatment with a saturated sodium bicarbonate solution and, after solvent evaporation, re-crystallization from ethanol or from 15% alcohol in water. It should be noted however that the Japanese patent makes no mention of the monohydrate form of argatroban being obtained and that for the compound the following characteristics are reported: m.p. 188-191° C.; molecular composition (theoretical/found) (%): C 54.31/54.01; H 7.13/6.98; N 16.52/16.61; I.R. (KBr) (cm−1) 3400; 1620; 1460; 1380. These analytical data, with the exception of the unreported melting point, are the same as those indicated in the cited patent documents describing a mixture of (2R,4R)-4methyl-[4N2-(3S-methyl-1,2,3,4-tetrahydro-8-quinolinesulphonyl)-L-arginyl]-2-piperidine carboxylic acid and (2R,4R)-4methyl-1-[N2-(3R-methyl-1,2,3,4-tetrahydro-8-quinolinesulphonyl)-L-arginyl]-2-piperidine carboxylic acid isomers of argatroban, but do not correspond to the melting point given in the publication, being the only document that identifies the monohydrate form of argatroban.

More recently, patent application CN 1,951,937 (filing date 10 Nov. 2006) described a method for preparing hydrated argatroban by treating argatroban with large quantities of water (more than 60 and up to 80 volumes of distilled water per gram of argatroban) at a temperature of 80-100° C. for a time of 0.5-1 hour and crystallization by cooling. The water content reported is comprised between 3.3 and 3.8% and the ratio of dextroisomer R to levoisomer S is R:S=63-67: 37-33.

Argatroban is a compound of wide therapeutic use, for which reason the need still exists to provide a compound of pharmaceutically acceptable quality obtained by easily industrialized and economically convenient methods. With regard to the monohydrate, this form is preferable for the applicative purpose since the anhydrous form is unstable and tends to become hydrated and/or wet. Moreover it crystallizes only with difficulty at the correct ratio between the diastereoisomers.

…..

the protection of 4-methylpiperidine (I) with (Boc)2O gives the carbamate (II), which is condensed with benzyl chloroformate by means of sec-butyl lithium and TMEDA in ethyl ether to yield (?-trans-1-(tert-butoxycarbonyl)-4-methylpiperidine-2-carboxylic acid benzyl ester (III). Deprotection of the NH group of (III) with HCl in ethyl acetate affords (?-trans-4-methylpiperidine-2-carboxylic acid benzyl ester (IV), which is condensed with the protected arginine derivative (V) by means of isobutyl chloroformate and TEA to provide the corresponding amide as a diastereomeric mixture. Resolution of this mixture by flash chromatography furnishes the desired diastereomer (VI), which is treated with HCl in ethyl acetate in order to remove the Boc-protecting group to yield compound (VII). Condensation of compound (VII) with 3-methylquinoline-8-sulfonyl chloride (VIII) by means of TEA in dichloromethane affords the expected sulfonamide (IX). Finally, this compound is submitted to hydrogenation with H2 over Pd/C in AcOH/ethanol in order to produce debenzylation, cleavage of the NO2 group and hydrogenation of the pyridine ring to yield argatroban.

………….

Argatroban, i.e., (2R,4R)-1-((2S)-5-((Aminoiminomethyl)amino)-1-oxo-2-((1,2,3,4-tetrahydro-3-methyl-8-quinolinyl)sulfonyl)amino) pentyl)-4-methyl-2-piperidine carboxylic acid, has two diastereoisomers: 21(R) and 21(S). Usually the ratio of 21(R) to 21(S) is 64-65: 36-35 (U.S. Pat. No. 6,440,417, Cossy. J., et al, Bioorganic & Medicine Chemistry Letters, 11 (2001), 1989-1992, Journal of pharmaceutical Sciences, Vol. 82, No. 6, 672 (1993)).

The structure formula of Argatroban is reported below:

• • 21(S) Argatroban, X=CH₃, Y═H;
  • 21(R) Argatroban, X=H, Y=CH₃;
  • Argatroban, 21(S): 21 (R)=35:65.

The chemical names of the two diastereoisomers mentioned above are:

• 21(S) Argatroban: (2R,4R)-1-((2S)-5-((Aminoiminomethyl)amino)-1-oxo-2-((((3S)-1,2,3,4-tetrahydro-3-methyl-8-quinolinyl)sulfonyl)amino)pentyl)-4-methyl-2-piperidine carboxylic acid (121785-72-6); and
• 21(R) Argatroban: (2R,4R)-1-((2S)-5-((Aminoiminomethyl)amino)-1-oxo-2-((((3R)-1,2,3,4-tetrahydro-3-methyl-8-quinolinyl)sulfonyl)amino)pentyl)-4-methyl-2-piperidine carboxylic acid (121785-71-5).

In 1978, S. Akamoto et al from Japanese Mitsubishi Chemical Corporation first disclosed the anti-thrombin activity of Argatroban monohydrate (U.S. Pat. No. 4,101,653). In the next 20 years, numerous researchers had in-depth studies on Argatroban about its biological activity and medicine values. In 1981, S. Akamoto compared Argatroban with heparin in vivo (Okamoto, S. et al., Biochem. Biophys. Res. Commun. 101, 440 (1981)); T. Kumoto disclosed its three-dimensional selective activity (Kumada, T. et al., Thromb. Res. 24, 285 (1981)). In 1984, R. Kumato made a clinical evaluation of hemodialysis of Argatroban (Kikumoto, R. et al., Biochemistry 23, 85 (1984)), and in 1986, he further disclosed that Argatroban can inhibit the thrombin activity of mammals, and can be used as active ingredient to treat and prevent thrombosis and as an inhibitor of platelet aggregation. Argatroban monohydrate can be used as a selective anti-thrombosis agent for treatment of chronic arterial blockage and cerebral thrombosis, etc (JP 61-48829). In 1992 and 1993, Taparelli and Jakubowski separately disclosed the reversibility of Argatroban in anti-thrombin (Taparelli, C., Trends Pharmacol. Sci., 1993, 14, 366, Jakubowski, J. A. et al, Rep. Med. Chem., 1992, 27, 99). In 1990s, many researchers such as L. R. Buch reported other related research (Buch, L. R., Cadiosvasc. Drug Rev., 1991, 9, 247, Strupcnewski, J. D. et al., Academic: San Diego, 1991; Vol. 26, p 299, Brundish, D. et al., J. Med. Chem. 1999; 42, 4584, Shebuski, R. J., Academic: San Diego, 1999; Vol. 26, p 98). In 1992, Argatroban monohydrate was first approved as an anti-thrombin medicine in Japan (Hijikata-Okunomiya, A., et al, Thromb. Hemostasis, 1992, 18, 135).

IRBESARTAN, SR 47436, BMS-186295

Avapro® (Bristol-Myers Squibb) and Karvea®
(Sanofi-Winthrop)

2-butyl-3-({4-[2-(2H-1,2,3,4-tetrazol-5-yl)phenyl]phenyl}methyl)-1,3-diazaspiro[4.4]non-1-en-4-one

138402-11-6  CAS NO

U.S. Patents 5,270,317 and 5,352,788, 6,162,922

The compound prepared according to US 5270317 is polymorph A

• Irbesartan is known by following chemical names:

  1. (a) 2-Butyl-3-[[2'-(1H-tetrazol-5-yl)[1,1'-biphenyl]-4-yl]methyl]-1,3-diazaspiro[4,4]non-1-en-4-one
  2. (b) 2-Butyl-3-[p-(o-1H-tetrazol-5-ylphenyl)benzyl]-1,3-diazaspiro[4,4]non-1-en-4-one
  3. (c) 2-n-butyl-4-spirocyclopentane-1-[(2'-(tetrazol-5-yl)biphenyl-4-yl) methyl]-2-imidazolin-5-one.
• The structural formula of Irbesartan is represented below.

  Irbesartan

• The synthesis of irbesartan is first disclosed in US5270317 (equivalentEP0454511 ) and subsequently, several other patents disclose the synthesis of irbesartan by different methods. Basically the synthesis of this molecule involves two common intermediates namely spiroimidazole and substituted 4′-bromomethylbiphenyl.
• US 5270317 describes preparation of irbesartan wherein 1-[(2'-cyanobiphenyl-4-yl)methyl]-2-n-butyl-4-spirocyclopentane-2-imidazolin -5-one which is reacted with tributyltin azide in xylene at reflux temperature for 66 hours to give a product which is isolated from the reaction mass as trityl irbesartan and then deprotected in methanol/THF mixture using 4N hydrochloric acid to get irbesartan.
• US5629331 describes a process for the preparation of irbesartan from 1-[(2'-cyanobiphenyl)4-yl)methyl]-2-n-butyl-4-spirocyclopentane-2-imidazolin-5-one using sodium azide, TEA.HCl in N-methylpyrrolidone. The product is isolated from the alkaline reaction mass after acidification to pH 4.7 to 5.8 and the crude product is recrystallised from IPA/water to get Form A and ethanol/water to get Form B.

Irbesartan (INN) /ɜrbəˈsɑrtən/ is an angiotensin II receptor antagonist used mainly for the treatment of hypertension. Irbesartan was developed by Sanofi Research (now part ofsanofi-aventis). It is jointly marketed by sanofi-aventis and Bristol-Myers Squibb under thetrade names Aprovel, Karvea, and Avapro.

It is marketed in Brazil by Sanofi-Aventis under the trade name Aprovel .

As with all angiotensin II receptor antagonists, irbesartan is indicated for the treatment ofhypertension. Irbesartan may also delay progression of diabetic nephropathy and is also indicated for the reduction of renal disease progression in patients with type 2 diabetes,^[1]hypertension and microalbuminuria (>30 mg/24 hours) or proteinuria (>900 mg/24 hours).^[2]

Irbesartan is also available in a combination formulation with a low dose thiazide diuretic, invariably hydrochlorothiazide, to achieve an additive antihypertensive effect. Irbesartan/hydrochlorothiazide combination preparations are marketed under similar trade names to irbesartan preparations, including Irda, CoIrda, CoAprovel, Karvezide,Avalide and Avapro HCT.

A large randomized trial following 4100+ men and women with heart failure and normal ejection fraction (>=45%) over 4+ years found no improvement in study outcomes or survival with irbesartan as compared to placebo.^[3]

BMS annual sales approx $1.3bn. Sanofi-aventis annual sales approx $2.1bn. In the United States, a generic version is available. Patent expired March 2012.

1. Lewis EJ, Hunsicker LG, Clarke WR, Berl T, Pohl MA, Lewis JB, Ritz E, Atkins RC, Rohde R, Raz I; Collaborative Study Group. (2001). “Renoprotective effect of the angiotensin-receptor antagonist irbesartan in patients with nephropathy due to type 2 diabetes”. N Engl J Med 345 (12): 851–60. doi:10.1056/NEJMoa011303.PMID 11565517.
2.  Rossi S, editor. Australian Medicines Handbook 2006. Adelaide: Australian Medicines Handbook; 2006. ISBN 0-9757919-2-3
3.  Massie BM, Carson PE, McMurray JJ, Komajda M, McKelvie R, Zile MR, Anderson S, Donovan M, Iverson E, Staiger C, Ptaszynska A (December 2008). “Irbesartan in patients with heart failure and preserved ejection fraction”. N. Engl. J. Med. 359 (23): 2456–67.doi:10.1056/NEJMoa0805450. PMID 19001508.

4……….C. A. Bernhart, P. M. Perreaut, B. P. Ferrari, Y. A. Muneaux,
J.-L. A. Assens, J. Clement, F. Haudricourt, C. F. Muneaux,
J. E. Taillades, M.-A. Vignal, J. Gougat, P. R. Guiraudou, C.
A. Lacour, A. Roccon, C. F. Cazaubon, J.-C. Brelihre, G. Le
Fur, D. Nisato, J. Med. Chem. 1993, 36, 3371–3380.
5…. K. F. Croom, M. P. Curran, K. L. Goa, Drugs 2004 64,
999–1028.
6… C. Bernhard, J.-C. Breliere, J. Clement, D. Nisato, P. M. Perreaut, C. F. Muneaux, (Elf Sanofi) US 5 270 317; Chem. Abstr. 1993, 119, 95560.
7. S. Chava, M. Bandari, K. S. Mathuresh, (Matrix Laboratories) WO 2005/122699; Chem. Abstr. 2005, 144, 88292.
5. S. Zupan~i~, A. Pe~avar, R. Zupet, (Krka) WO 2006/073376;
Chem. Abstr. 2006, 145, 124576.
8. C. V. Kavitha, S. L. Gaonkar, J. N. Chandra, S. Narendra, C.
T. Sadashiva, K. S. Rangappa, Bioorg. Med. Chem. 2007, 15,
7391–7398.
9. S. Rádl, J. Stach, O. Klecán, (Zentiva) WO 2005/021535;
Chem. Abstr. 2005, 142, 298118.
10. B. Satyanarayana, Y. Anjaneyulu, P. Veerasomaiah, P. P.
Reddy, Heterocycl. Commun. 2007, 13, 223–228.
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A. Rani, A. Naidu, Synth. Commun. 2007, 37, 2897–2905.
12. J. Havlí~ek, Z. Mandelová, R. Weisemann, I. Strˇelec, S.
Rádl, Collect. Czech. Chem. Commun. 2009, 77, 347.

Irbesartan of formula (I).

The chemical name of Irbesartan is 2-Butyl-3-[[2'-(lH-tetrazol-5-yl)[l,l'-biphenyl]-4- yl]methyl]-l,3-diazaspiro[4,4]non-l-en-4-one and formula is C₂SH₂SN₆O and molecular weight is 428.53. The current pharmaceutical product containing this drug is being sold by Sanofi Synthelabo using the tradename AVAPRO, in the form of tablets. Irbesartan is useful in the treatment of diabetic neuropathy, heart failure therapy and hypertension. Irbesartan is angiotension II type I (AΙIi)-receptor antagonist. Angiotension II is the principal pressor agent of the rennin-angiotension system and also stimulates aldosterone synthesis and secretion by adrenal cortex, cardiac contraction, renal resorption of sodium, activity of the sympathetic nervous system and smooth muscle cell growth. Irbesartan blocks the vasoconstrictor and aldosterone- secreting effects of angiotension II by selectively binding to the ATi angiotension II receptor. U.S. Pat. Nos. 5,270,317 and 5,559,233 describes a process for the preparation of N- substituted heterocyclic derivatives which involves reacting a heterocyclic compound of the formula

with a (biphenyl-4-yl)methyl derivative of the formula

wherein R₁, R₂, R₃, R₄, R₅, and t, z and Hal have the meanings given in said U.S. Pat. No.

5,270,317, in the presence of an inert solvent such as DMF, DMSO or THF, with a basic reagent, for example KOH, a metal alcoholate, a metal hydride, calcium carbonate or triethylamine. The products of the reaction were purified by chromatography.

U.S. Pat. Nos. 5,352,788, and 5,559,233, and WO 91/14679 also describe identical alkylation of the nitrogen atom of the heterocyclic compound with the halo-biphenyl compound using the same inert solvent and the same basic reagents.

• US5629331 describes a process for the preparation of irbesartan from 1-[(2'-cyanobiphenyl)4-yl)methyl]-2-n-butyl-4-spirocyclopentane-2-imidazolin-5-one using sodium azide, TEA.HCl in N-methylpyrrolidone. The product is isolated from the alkaline reaction mass after acidification to pH 4.7 to 5.8 and the crude product is recrystallised from IPA/water to get Form A and ethanol/water to get Form B.
• WO 2005/051943 A1 describes a process for the preparing irbesartan wherein 1-[(2'-cyanobiphenyl-4-yl)methyl]-2-n-butyl-4-spirocyclopentane-2-imidazolin-5-one is reacted with tributyltin chloride, sodium azide and TBAB in toluene at reflux temperature for 20 hours. Product is isolated from the reaction mass as trityl irbesartan and then deprotected in methanol and formic acid to get irbesartan.
• WO 2006/023889 describes a method for preparing irbesartan, wherein 1-(2′-cyanobiphenyl-4-yl)methyl)-2-n-butyl-4-spirocyclopentane-2-imidazolin-5-one is reacted with sodium azide and triethylamine hydrochloride in N-methyl-2-pyrrolidone to give irbesartan.
• WO 2005/113518 describes a process for preparing irbesartan wherein cyano irbesartan in xylene, is reacted with tributyltin chloride and sodium azide at reflux temperature till reaction is completed followed by aqueous work-up and recrystallization to give irbesartaN
• The process involving use of zinc salt for the transformation of nitrile to tetrazole is a safe and efficient process as reported in JOC (2001) 66, 7945-50. The use of zinc salt for transforming nitrile to tetrazole has also been published in WO9637481 and US5502191 

Also Canadian Patent No. 2050769 describes the alkylation of the nitrogen atom of the heterocycle of the formula

with a compound of the formula

wherein X, R₁, Z₁ and Z₆ have the meanings given therein, in the presence of N,N- dimethylformamide and a basic reagent, such as alkali metal hydrides for example sodium or potassium hydride.

All of the above identified patents describe alkylation in solvents, such as N₅N- dimethylformamide or DMSO, etc. in the presence of a basic reagent, for example, a metal hydride or a metal alcoholate etc. The strong bases, such as metal hydride or a metal alcoholate require anhydrous reaction conditions. Since N,N-dimethylformamide is used as a solvent, its removal requires high temperature concentration by distillation, which can result in degradation of the final product. The product intermediate is also purified by chromatography which is commercially not feasible and cumbersome on large scale. Another process given in Canadian Patent No. 2050769 provides synthetic scheme as herein given below.

This process comprises the steps of protecting carboxylic group present on cyclopentane ring which is deprotected in consecutive step by vigourous hydrogenation condition in autoclave which is operationally difficult at a large scale.

US Patent No. 2004242894 also discloses the process of preparation of lrbesartan from 4- bromomethyl biphenyl 2′-(lH-tetrazol (2-triphenylmethyl) 5-yl) and Ethyl ester of 1- Valeramido cyclopentanecarboxylic acid in toluene in presence of base and PTC, and then hydrolyzing the protecting group. However this requires chromatographic purification.

This patent also discloses the process of preparation of tetrazolyl protected lrbesartan using 2,6 lutidine and oxalylchloride in toluene. However in this process the yield is as low as 30%.

US Patent No. 2004192713 discloses the process of preparation of lrbesartan by condensing the two intermediates via Suzuki coupling reaction. The reaction scheme is as given herein below.

However, this process has several disadvantages such as use of the reagents like butyl lithium and triisobutyl borate at low temp such as -20 to -30°C under Argon atmosphere condition which is difficult to maintain at commercial scale.

WO2005113518 discloses the process of preparation of Irbesartan by condensing n- pentanoyl cycloleucine (V) with 2-(4-aminomethyl phenyl) benzonitrile (VI) using dicyclocarbodiimide (DCC) and 1 -hydroxy benzotriazole as catalyst to give an open chain intermediate of formula (VIII) which is then cyclized in the presence of an acid, preferably trifluoro acetic acid to give cyano derivative of formula (VII) and which in turn is converted to Irbesartan by treating it with tributyl tin chloride and sodium azide.

In this application further describes another process comprising the steps of reacting 2- butyl-l,3-diazasρiro[4,4]non-l-en-4-one monohydrochloride (A) with 4-bromobenzyl bromide (B) in presence of base and solvent to give 3-[4-bromobenzyl]-2-butyl-l,3- diazaspiro[4,4]non-l-en-4-one (C) which is condensed with 2-[2'-(triphenylmethyl-2'H- tetrazol-5'-yl)phenyl boronic acid in the presence of tetrakis triphenyl phosphine palladium and base to give lrbesartan (I). However these processes suffer with several disadvantages such as it uses trifluoroacetic acid for the cyclization step which is highly corrosive material. The process requires an additional step of activation by DCC. This step not only increases number of steps but also create problem in handling DCC at an industrial scale as it is highly prone to hazard which makes the process least preferred on a large scale production of lrbesartan. Further it uses phenyl boronic acid derivative and triphenyl phosphine complex which are harmful for the skin and eye tissue and also harmful for respiratory system. Tetrakis triphenyl phosphine palladium is also a costly material which increases overall cost for the production of lrbesartan. Moreover the yield is as low as 22%. All the above patents/applications are incorporated herein as reference. In summary, prior art relating to the process for the preparation of lrbesartan suffers with several drawbacks such as i) It requires chromatographic purification of intermediates at various stages. ii) It requires specific autoclave conditions for a deprotection of protecting group. iii) It requires maintaining low temperature conditions such as -30⁰C and requires special handling care and air and moisture tight condition with the reagents such as butyl lithium and triisobutyl borate. iv) It uses hazardous and highly corrosive reagents, v) It suffers low yield problem. vi) All the process is having more number of reaction steps.

• Irbesartan is described in Bernhart et al., U.S. Patent No. 5,270,317 
• Irbesartan, is a potent, long-acting angiotensin II receptor antagonist which is particularly useful in the treatment of cardiovascular ailments such as hypertension and heart failure. Its chemical name is2-n-butyl-4-spirocyclopentane-1-[(2'-(tetrazol-5-yl)biphenyl-4-yl)methyl]-2-imidazolin-5-one.

Irbesartan is an antihypertensive agent known from EP 454511. From EP 708103, which discloses their X-ray spectra, two polymorphs are known where form A can be produced form a solvent system containing less than 10% of water, while Form B from a system with more than 10% of water. The specific morphological variant of form A can be prepared having properties as disclosed in EP 1089994. Additional form has been disclosed in WO 04089938. Amorphous irbesartan is known from WO 03050110. It is said that Irbesartan produced as taught in EP 454511 is a fluffy material with relatively low bulk and tap densities and undesirable flow characteristics, which consequently has unadvantageous electrostatic properties, among them a high chargeability as measured by tribugeneration between -30 and -40 nanocoulomb/g (10^’9As/g). Alternativelyirbesartan could be prepared by complex process using sonifications and/or temperature oscillations according to EP 1089994 to exhibit a chargeability as measured by tribugeneration between -0 and -10 nanocoulomb/g.

According to EP 454511 a solid composition in form of tablets is prepared by mixing the active ingredient with a vehicle such as gelatine, starch, lactose, magnesium stearate, talc, gum Arabic or the like and can be optionally coated. The compositions containing from 20% to 70% by weight of irbesartan are known from EP 747050.

WO 04/007482 teaches the acidification to pH 2 – 3,5 of trityl irbesartan, which is sufficient to remove the protecting group, but not to convert into an acid addition salt; WO 04/065383 is likewise silent on hydrohalide acid addition salts. WO
06/011859 relates to the preparation of a hydrochloride salt of irbesartan in order to incorporate it into a pharmaceutical formulation. W099/38847 mentions optional conversion of irbesartan into hydrochloride, hydrobromide or hydrogen sulfate salts

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WO2006023889A2

Example 1Preparation of Compounds of formula IVa and IVb:

• A jacketed 1,000 mL 3-neck flask was charged with 4′-methylbiphenyl-2-carbonitrile (Compound 1, 100.0 g) and CH₂CI₂ (500 mL) under nitrogen. To a 500 mL Erlenmeyer flask with magnetic stirrer, sodium bromate (NaBrO₃; 31.2 g) was dissolved in water (170 mL). The NaBrO₃ solution was transferred to the 1,000 mL flask and the reaction mixture was cooled to about 5 °C or less. Aqueous HBr solution (48 %, 105.0 g) was added to the 1,000 mL flask and the resulting reaction mixture was recycled though a UV lamp reactor. The reaction mixture was kept at 0-20 °C and the recycling was continued until the reaction was deemed complete by HPLC. Optionally, additional sodium bromate and hydrogen bromide may be added. The relative amounts of Compound 2 and Compound 3 were about 80-90% and about 10-20% respectively. Aqueous sodium metabisulfite solution (2.0 g of in 10 mL water) was added to the reaction mixture. Allow the phases to settle and the methylene chloride phase was washed with water and used in the next step without further purification.

Example 2Preparation of Compound II:

• A 1L 3-neck flask was charged with Compound V (134.0 g), MTBAC (5.0 g) and CH₂Cl₂ (170 mL) and cool to -5 to 5 °C. An aqueous solution of KOH (182.6 g in 212 mL water) was added slowly to the 1L flask and the reaction temperature was kept at ≤ 5 °C. The methylene chloride solution of Compound IVa and Compound IVb from Example 1 was added to the reaction mixture slowly, while maintaining the temperature at 0-10 °C. Diethyl phosphite (39.66g) was added drop wise at 0-10 °C. Check the reaction mixture for completion of the reduction reaction, and additional diethyl phosphite may be added.
• The reaction mixture was allowed to warm to ambient (20-30 °C) and agitated until the reaction was deemed complete by HPLC. Water (150 mL) was added and the phases were separated. The organic layer was extracted with water (230 mL) and polish filtered.
• The methylene chloride (which contained the crude Compound II) was distilled off and exchanged with about 400 mL of methyl tert-butyl ether (MTBE) (optionally, the MTBE recycled from washing below can be used here). Upon cooling, crystallization occurred (optionally seeds were added) and after further cooling to below 25°C, crystals of Compound II were isolated, washed with MTBE and dried in vacuum at a temperature of less than 60°C. HPLC retention time: 18.126 min. Typically, the yield was about 85 to about 88%. Alternatively, IPA could be used as the crystallization and washing solvent
• Optionally, the solvent (i.e., MTBE or IPA) used to wash the crystals of Compound II above can be recycled and used to crystallize the crude Compound II in the next batch. Since the washed solvent contains Compound II as well as impurities, it was surprisingly found that the washed solvent can be recovered and used again in crystallizing the crude compound of formula II in the next batch without sacrificing its purity while increasing its yield.

Example 3Preparation of Compound I:

• A reactor was charged with Compound II (1 kg), triethylamine chlorhydrate (0.713 kg), sodium azide (0.337 kg) and N-methyl pyrrolidinone (2.07 kg), and the reaction mixture was heated to about 122°C under stirring. After completion of the reaction as determined by HPLC, the reaction mixture was cooled to about 45°C, and an aqueous solution of sodium hydroxide (35%, 5.99 kg) and water (3.0 kg) were added, the resulting mixture was stirred at a temperature between about 20 and about 40°C for about 0.5 hours. The aqueous phase was discarded and the organic phase was treated with toluene (1.73 kg) and water (5.0 kg), and stirred for about 0.5 hours at about 20 – about 30°C. The toluene phase was discarded and the aqueous phase was washed with ethyl acetate (1.8 kg) and treated with aqueous HCl until pH was adjusted to about 4.8 – about 5.2. Precipitation occurred and the resulting suspension was stirred for about 1 hour at about 20 – about 25°C. The precipitation was collected and washed with water three times (1.0 kg x 3). The crude wet product was recrystallized using a mixture of iso-propanol (0.393 kg) and water (4.5 kg). HPLC retention time: 11.725 min. The yield for Compound I was about 87%.

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SPECTRAL DATA

The ESI mass spectrum of irbesartan showed a protonated molecular ion peak at m/z 429.3 confirming the molecular weight 428. The fragmentation pattern of parent ion 429.3 showed the fragment ions at m/z 385.9, 235.1, 207, 195.4, 192.1, 180.2 and 84

The FT-IR spectrum exhibited a characteristic stretching absorption band at 1732 cm-1 for the carbonyl group of amide functionality. The presence of this band at higher frequency was due to the ring stretching due to five member ring system. Another band at 1614cm-1 was due to C=N stretching vibrations

1H and 13C- NMR were recorded using DMSO-d6 as a solvent. In 1H-NMR the signal due to tetrazole NH proton was not detected may probably due to the tautomerism.

SEE

http://orgspectroscopyint.blogspot.in/2013/12/irbesartan-spectral-data.html

DP 1 IS IMPURITY

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NMR

WO2007049293A1

¹H-NMR (DMSO d6): δppm 0.78 (t, 3H); 1.17-1.30 (sex, 2H); 1.40-1.50 (quent, 2H); 1.64-1.66 (m, 2H); 1.80-1.82 (m, 6H); 2.22-2.29 (t, 2H); 4.67 (s, 2H); 7.07 (s, 4H); 7.50- 7.68 (m, 4H) M⁺: 429.6

,…………………..

m.p:181-182oC,

IR (KBr, cm-1) 1732 (C=O), 1616 (C=N); 1H NMR (DMSO-d6): δ 7.95–7.32 (m, 8 H), 4.80 –4.60 (s, 2 H), 3.60– 3.00 (br s, 1 H), 2.40– 2.20 (t, 2 H , J = 6.04 Hz), 2.00– 1.60 (m, 8 H),1.60–1.45 (quint, 2 H), 1.40– 1.20 (sext, 2 H), 0.91–0.70 (t, 3H, J = 7.41 Hz);

13C-NMR (DMSOd6): δ 186.5, 162.0,155.9, 141.9, 139.2, 137.2. 131.9, 131.4, 130.1, 128.7, 127.1, 124.3, 76.7, 43.1,
37.7, 28.3, 27.4, 26.3, 22.4, 14.5;

MS: m/z= 429 [M+1];

Anal. Calcd for C25H28N6O : C, 70.07; H,
6.59; N, 19.61. Found: C, 70.04; H, 6.57; N, 19.58.

http://www.acgpubs.org/OC/2011/Volume%204/Issue%201/13-OC-1106-199.pdf

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HPLC condition:

Column: Alltima C18 (Alltech 88050) 15.0cm in length x 4.6mm in internal diameter and 5 micron particle size;
Column temperature: 40 C;
Solvent A: Buffer solution A 1.1 g of heptanesulfonic acid in 1 liter of water and adjust the pH to 2.5;
Solvent B: Methanol Flow rate: 1.2mL/min;
Gradient Elution Condition:
Time% A % %B
0 min 50 50
35 min 15 85
Detector: 240 nm;
Injection volume: 10 uL.

The chromatographic purity of
the compounds was analyzed using Agilent 1200 series HPLC instrument under the following conditions:
Column : Symmetry C18, 4.6 × 75 mm, 3.5 µm
Mobile phase : Eluent A: Deionized water, Eluent B: HPLC grade Methanol
Chromatographic Conditions
a. Column temperature : Ambient
b. Sample compartment : Ambient
c. Detector : 225 nm
d. Injection volume : 10 µL
e. Run time : 45 minutes
f. Flow rate :1.0 mL/min
g. Injector :Auto sampler with variable volume injector
h. Diluent : HPLC grade Acetonitrile

Iloperidone (Fanapt), ILO-522, HP-873, Zomaril, 133454-47-4, antipsychotic

1-[4-[3-[4-(6-Fluoro-1,2-benzisoxazol-3-yl)-1-piperidinyl]propoxy]-3-methoxyphenyl]ethanone; 1-[3-(4-Acetyl-2-methoxyphenoxy)propyl]-4-(6-fluoro-1,2-benzisoxazol-3-yl)piperidine; 4′-[3-[4-(6-Fluoro-1,2-benzisoxazol-3-yl)-1-piperidinyl]propoxy]-3′-methoxyacetophenone

Aventis Pharma (Originator), Novartis (Licensee), Titan (Licensee)Vanda Pharmaceuticals (Licensee)

Iloperidone(Fanapt) is a monoamine directed towards acting upon and antagonizing specific neurotransmitters, particularly multiple dopamine and serotonin receptor subtypes.

syn

J.T. Strupczewski, K.J. Bordeau, Y. Chiang, E.J. Glamkowski, P.G.
Conway, R. Corbett, H.B. Hartman, M.R. Szewczak, C.A. Wilmot andG.C. Helsley, J. Med. Chem., 38, 1119 (1995).

US 4355037
V. Miklos, WO Patent 031497 (2010).
J.T. Strupczewski, EP Patent 0402644 (1990)

The product is protected by the U.S. Pat. No. 5,364,866, U.S. Pat. No. RE 39198 E and EP 402644 B1.U.S. Pat. No. 5,364,866 and U.S. Pat. No. 5,663,449.EP 542136, EP 612318, EP 730452, JP 95501055, JP 97511215, US 5364866, US 5776963, WO 9309102, WO 9511680.US 4355037,EP 0542136; EP 0612318; EP 0730452; EP 0957102; EP 0959075; EP 0959076; EP 0963984; JP 1995501055; JP 1997511215; US 5364866; US 5776963; WO 9309102; WO 9511680

The first reported synthetic method for Iloperidone is described in patent EP 402644 A1.

In U.S. Patent US5776963 and patent family EP4 (^ 644, there is disclosed a method for preparing iloperidone,

The synthetic route is as follows:

The reaction of piperidine-4-carboxylic acid (I) with formic acid and acetic anhydride gives 1-formylpiperidine-4-carboxylic acid (II), which is treated with SOCl2 and acetic anhydride to yield the corresponding acyl chloride (III). The Friedel-Crafts condensation of (III) with refluxing 1,3-difluorobenzene (IV) by means of AlCl3 affords 4-(2,4-difluorobenzoyl)-1-formylpiperidine (V), which is treated with hydroxylamine in refluxing ethanol to give the corresponding oxime (VI). The cyclization of (VI) by means of NaH in hot THF/DMF yields 6-fluoro-3-(1-formylpiperidin-4-yl)-1,2-benzisoxazole (VII), which is treated with HCl in refluxing ethanol to afford 6-fluoro-3-(4-piperidyl)-1,2-benzisoxazole (VIII). Finally, this compound is condensed with 4-(3-chloropropoxy)-3-methoxyacetophenone (IX) by means of K2CO3 in hot DMF. The intermediate 4-(3-chloropropoxy)-3-methoxyacetophenone (IX) can be obtained by condensation of 4-hydroxy-3-methoxyacetophenone (IX) with 3-chcloropropyl bromide (X) by means of NaH or K2CO3 in DMF.

Iloperidone, also known as Fanapt, Fanapta, and previously known as Zomaril, is an atypical antipsychotic for the treatment ofschizophrenia.

It was approved by the U.S. Food and Drug Administration (FDA) for use in the United States on May 6, 2009.

It’s not yet approved in India.

Hoechst Marion Roussel Inc. made initial inquiries into the drug; however, in May 1996, they discontinued research, and in June 1997 gave research rights to Titan Pharmaceuticals. Titan then handed over worldwide development, manufacturing and marketing rights to Novartis in August 1998. On June 9, 2004, Titan Pharmaceuticals announced that the Phase III development rights have been acquired by Vanda Pharmaceuticals. The original launch date was scheduled for 2002. On November 27, 2007, Vanda Pharmaceuticals announced that the U.S. Food and Drug Administration (FDA) had accepted their New Drug Application for iloperidone, confirming the application is ready for FDA review and approval. On July 28, 2008, the FDA issued a “Not Approvable” letter to Vanda Pharmaceuticals concerning the drug, stating that further trials are required before a decision can be made concerning marketed usage of iloperidone.

Iloperidone won FDA approval for use treating schizophrenia in the United States on May 6, 2009

Iloperidone (1-[4-[3-[4-(6-fluoro-1,2-benzisoxazole-3-yl)-1-piperidinyl]propoxy]-3-methoxyphenyl]ethanone) is an atypical new-generation antipsychotic medicament belonging to the class of piperidinyl-benzisoxazole derivatives, which is used to treat schizophrenia, bipolar disorder and other psychiatric conditions. Iloperidone acts as a serotonin/dopamine receptor antagonist (5-HT_2A/D₂).

The synthesis of iloperidone is described in USRE39198 (corresponding to EP 0 402 644 example 3) according to the following synthesis scheme:

In agreement with said patent, the intermediate isolated, 1-[4-(3-chloropropoxy)-3-methoxyphenyl]ethanone, is reacted with 6-fluoro-3-(4-piperidinyl)-1,2-benzisoxazole hydrochloride in N,N-dimethyl formamide at 90° C. for 16 hours. When the reaction is complete, the mixture is poured into water and extracted with ethyl acetate. The crude product thus obtained is crystallised twice from ethanol to give crystallised iloperidone with a total yield of 58%.

The yield of this process is very low; moreover, the process begins with two isolated intermediates, and requires an aqueous extractive work-up step with an increase in volumes and consequent reduction in the productivity and efficiency of the process. Said process also requires a double crystallisation step to obtain a beige product. The quality levels obtained are not described in the text of the example, but a beige color does not suggest a high-quality product, as iloperidone is a white substance.

The synthesis of intermediate 1-[4-(3-chloropropoxy)-3-methoxyphenyl]ethanone is disclosed in U.S. Pat. No. 4,366,162. Example 1 describes the preparation of said intermediate by reacting acetovanillone with 1-bromo-3-chloropropane in acetone with potassium carbonate. At the end of the reaction the resulting product is purified by distillation and obtained as an oily intermediate which is left to stand in order to obtain the solid intermediate.

The synthesis of intermediate 1-[4-(3-chloropropoxy)-3-methoxyphenyl]ethanone is also disclosed in U.S. Pat. No. 4,810,713. Preparation 12 describes the synthesis of said intermediate from acetovanillone and 1-bromo-3-chloropropane in sodium hydroxide alkalinized water. At the end of the reaction the product obtained is extracted in toluene, the organic phases are washed with basic aqueous solutions and finally, the intermediate 1-[4-(3-chloropropoxy)-3-methoxyphenyl]ethanone is crystallised with the aid of diisopropyl ether. The intermediate isolated is then recrystallised twice from cyclohexane and twice from petroleum ether.

An alternative process for the synthesis of iloperidone is reported in CN 102070626.

Scheme 2 shows the synthesis procedure:

The decision to alkylate acetovanillone with 1-chloro-3-propanol requires an extra synthesis step (to convert the OH group to an OR leaving group) compared with the procedure reported by the combination of patents USRE39198 (EP402644) and U.S. Pat. No. 4,366,162/U.S. Pat. No. 4,810,713, making said process less efficient from the economic standpoint.

WO2011061750 discloses an alternative iloperidone synthesis process as reported in Scheme 3:

Said process uses reagents such as methyl magnesium chloride to effect the Grignard reaction to convert the aldehyde group to a secondary alcohol group, which are much more complicated to manage on an industrial scale than the synthesis methods previously described. Moreover, the oxidation reaction of the next step uses reagents such as chromic acid or potassium permanganate, which have a very high environmental impact and very low industrial applicability.

WO2011055188 discloses a process for the synthesis of iloperidone comparable to the one reported in USRE39198 from two isolated intermediates 1-[4-(3-chloropropoxy)-3-methoxyphenyl]ethanone and 6-fluoro-3-(4-piperidinyl)-1,2-benzisoxazole hydrochloride. The same patent application also gives preparation examples of the intermediate 1-[4-(3-chloropropoxy)-3-methoxyphenyl]ethanone isolated as crystalline solid by procedures similar to those known in the literature.

CN 101824030 reports an iloperidone synthesis method similar to that of CN 102070626 which involves the same problems of inefficiency due to the additional step of inserting the leaving group required for alkylation with 6-fluoro-3-(4-piperidinyl)-1,2-benzisoxazole hydrochloride.

CN 101781243 discloses an alternative iloperidone synthesis process as reported in Scheme 4.

Said process is not advantageous compared with the preceding processes as the intermediate with the oxime group, due to the nature of this functional group, is particularly liable to degradation due to the action of numerous factors such as the presence of metals, acid pHs and basic pHs.

CN101768154 discloses a process for the synthesis of iloperidone comparable to the one reported in USRE39198 from two isolated intermediates, 1-[4-(3-chloropropoxy)-3-methoxyphenyl]ethanone and 6-fluoro-3-(4-piperidinyl)-1,2-benzisoxazole hydrochloride.

CN 101735208 describes a process for the synthesis of iloperidone comparable to the one reported in CN 101781243, namely through the intermediate with the functional oxime group.

IN 2007MU01980 discloses a process for the synthesis of iloperidone comparable to the one reported in USRE39198 from two isolated intermediates, 1-[4-(3-chloropropoxy)-3-methoxyphenyl]ethanone and 6-fluoro-3-(4-piperidinyl)-1,2-benzisoxazole hydrochloride.

WO 2010031497 describes an alternative iloperidone synthesis process as reported in Scheme 5.

The considerable economic disadvantage of the process reported in WO2010031497 is based on the fact that by reversing the order of alkylation and performing that of intermediate 6-fluoro-3-(4-piperidinyl)-1,2-benzisoxazole hydrochloride first, a greater loss of yield is generated on this intermediate which, according to the literature, is more difficult to synthesise and consequently more expensive than the intermediate 1-[4-(3-chloropropoxy)-3-methoxyphenyl]ethanone, with a globally greater economic inefficiency of the iloperidone preparation process.

CN 102212063 discloses a process for the synthesis of iloperidone with the same arrangement of the synthesis steps as patent application WO 2010031497.

WO2011154860 describes a process for the synthesis of iloperidone wherein a phase transfer catalyst is used to prepare the intermediate 1-[4-(3-chloropropoxy)-3-methoxyphenyl]ethanone which, as in all the other preparation examples previously described, is crystallised, isolated and dried before use in the next step with 6-fluoro-3-(4-piperidinyl)-1,2-benzisoxazole hydrochloride. Scheme 6 shows the synthesis scheme of the process of WO2011154860.

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http://www.google.com/patents/US20100076196

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http://www.google.com/patents/US20130261308

UPLC-MS [M+H+]=427

1H-NMR (in DMSO) (chemical shifts expressed in ppm with respect to the TMS signal): 2.06-1.78 (6H, m); 2.13 (2H, m); 2.49 (2H, t); 2.52 (2H, m); 2.97 (2H, m); 3.11 (1H, tt); 3.83 (3H, s); 4.12 (2H, t); 7.06 (1H, d); 7.22 (1H, m); 7.46 (1H, d); 7.61-7.58 (2H, m); 7.94 (1H, dd).

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http://www.asianjournalofchemistry.co.in/User/ViewFreeArticle.aspx?ArticleID=25_10_2

n oxide impurity

m.p. 155-157 ºC;

FT-IR (KBr, νmax, cm-1):
3083, 2958, 2878, 1655, 1606, 1584, 1509, 1467, 1419, 1348,1273, 1223, 1182, 1143, 1121, 1032, 971, 957, 881, 857, 813,
802;

1H NMR (300 MHz, CDCl3) δ 1.89-1.93 (m, 2H), 2.31-2.40 (m, 2H), 2.55 (s, 3H), 2.60-2.72 (m, 2H), 3.29-3.52 (m,
2H), 3.29-3.52 (m, 2H), 3.29-3.52 (m, 2H), 3.29-3.52 (m, 1H),3.85 (s, 3H), 4.23(t, 2H, J = 6.0 Hz), 7.11 (d, 1H, J = 8.4 Hz),7.30-7.36 (m, 1H), 7.62-7.65 (m, 1H), 7.71-7.74 (dd, J = 9.3and 2.0 Hz, 1H), 8.02-8.07 (dd, J = 8.7 and 5.4 Hz, 1H);

13C
NMR (75 MHz, CDCl3) δ 22.13, 24.70, 26.35, 31.49, 55.54,63.21, 67.07, 67.82, 97.51, 110.35, 111.86, 112.67, 123.11,
123.67, 129.95, 148.63, 152.22, 160.79, 163.10, 163.69,196.40;

MS (ESI, m/z): 443 [M + H]+. Anal. calcd. (%) for
C24H27N2O5F (442.19): C, 65.15; H, 6.15; N, 6.33; found (%):C, 65.11; H, 6.09; N, 6.29.

FANAPT is a psychotropic agent belonging to the chemical class of piperidinyl-benzisoxazole derivatives. Its chemical name is 4′-[3-[4-(6-Fluoro-1,2-benzisoxazol-3-yl)piperidino]propoxy]-3′-methoxyacetophenone. Its molecular formula is C₂₄H₂₇FN₂O₄ and its molecular weight is 426.48. The structural formula is:

Iloperidone is a white to off-white finely crystalline powder. It is practically insoluble in water, very slightly soluble in 0.1 N HCl and freely soluble in chloroform, ethanol, methanol, and acetonitrile.

Rilpivirine

500287-72-9  cas no

4-{[4-({4-[(E)-2-cyanovinyl]-2,6-dimethylphenyl}amino)pyrimidin-2-yl]amino}benzonitrile

Rilpivirine (TMC278, trade name Edurant) is a pharmaceutical drug, developed byTibotec, for the treatment of HIV infection.^[1][2] It is a second-generation non-nucleoside reverse transcriptase inhibitor (NNRTI) with higher potency, longer half-life and reducedside-effect profile compared with older NNRTIs, such as efavirenz.^[3][4]

Rilpivirine entered phase III clinical trials in April 2008,^[5][6] and was approved for use in the United States in May 2011.^[7] A fixed-dose drug combining rilpivirine with emtricitabine andtenofovir, was approved by the U.S. Food and Drug Administration in August 2011 under the brand name Complera.^[8]

Like etravirine, a second-generation NNRTI approved in 2008, rilpivirine is a diarylpyrimidine(DAPY). Rilpivirine in combination with emtricitabine and tenofovir has been shown to have higher rates of virologic failure than Atripla in patients with baseline HIV viral loads greater than 100,000 copies.

• Rilpivirine bound to proteins in the PDB

EDURANT (rilpivirine, Janssen Therapeutics) is a non-nucleoside reverse transcriptase inhibitor (NNRTI) of human immunodeficiency virus type 1 (HIV-1). EDURANT is available as a white to off-white, film-coated, round, biconvex, 6.4 mm tablet for oral administration. Each tablet contains 27.5 mg of rilpivirine hydrochloride, which is equivalent to 25 mg of rilpivirine.

The chemical name for rilpivirine hydrochloride is 4-[[4-[[4-[(E)-2-cyanoethenyl]-2,6-dimethylphenyl]amino]2-pyrimidinyl]amino]benzonitrile monohydrochloride. Its molecular formula is C₂₂H₁₈N₆ • HCl and its molecular weight is 402.88. Rilpivirine hydrochloride has the following structural formula:

Rilpivirine hydrochloride is a white to almost white powder. Rilpivirine hydrochloride is practically insoluble in water over a wide pH range.

Each EDURANT tablet also contains the inactive ingredients croscarmellose sodium, lactose monohydrate, magnesium stearate, polysorbate 20, povidone K30 and silicified microcrystalline cellulose. The tablet coating contains hypromellose 2910 6 mPa.s, lactose monohydrate, PEG 3000, titanium dioxide and triacetin.

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papers

Sun, et al.: J. Med. Chem., 41, 4648 (1998),

Kashiwada, et al.: Bioorg. Med. Chem. Lett., 11, 183 (2001)

Journal of Medicinal Chemistry, 2005 ,  vol. 48,  6  , pg. 2072 – 2079

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patents

WO201356003, WO200635067,

WO2013038425 

The following PCT Publications describe the synthesis of Rilpivirine:

WO03016306, WO2005021001, WO2006024667, WO2006024668, W02994916581, WO2009007441, WO2006125809, and WO2005123662. [0006] Crystalline Rilpivirine base Forms I and II are described in the US Patent

Publication: US2010189796. Crystalline Rilpivirine HC1, Forms A, B, C, and D, are described in the US Patent Publications: US2009/012108, and US2011/0008434. Rilpivirine fumarate and a synthesis thereof are disclosed in WO2006024667.

country……………….patent……………approved……………expiry

Rilpivirine and its hydrochloride salt were disclosed in U.S. patent no. 7,125,879.Process for the preparation of rilpivirine was disclosed in U.S. patent no. 7,399,856 (’856 patent). According to the ’856 patent, rilpivirine can be prepared by reacting the (E)-3-(4-amino-3,5-dimethylphenyI)acrylonitrile hydrochloride of formula II with 4-(4-chloropyrimidin-2-ylamino)benzonitrile of formula III-a in the presence of potassium carbonate and acetonitrile under reflux for 69 hours. The synthetic procedure is illustrated in scheme I, below: Scheme 1 Process for the preparation of rilpivirine was disclosed in U.S. patent no. 7,705,148 (Ί48 patent). According to the Ί48 patent, rilpivirine can be prepared by reacting the 4-[[4-[[4-bromo-2,6-dimethylphenyl]amino]-2- pyrimidinyl]amino]benzonitrile with acrylonitrile in the presence of palladium acetate, Ν,Ν-diethylethanamine and tris(2-methylphenyl)phosphine in acetonitrile. According to the Ί48 patent, rilpivirine can be prepared by reacting the compound of formula IV with 4-(4-chloropyrimidin-2-ylamino)benzonitrile formula Ill-a in the presence of hydrochloric acid and n-propanol to obtain a compound of formula Vll, and then the compound was treated with acetonitrile and potassium carbonate under reflux for 69 hours. The synthetic procedure is illustrated in scheme II, below: Rilpivirine Scheme II U.S. patent no. 7,563,922 disclosed a process for the preparation of (E)-3-(4- amino-3,5-dimethylphenyl)acrylonitrile hydrochloride. According to the patent, (E)-3-(4- amino-3,5-dimethylphenyl)acrylonitrile hydrochloride can be prepared by reacting the 4- iodo-2,6-dimethyl-benzenamine in Ν,Ν-dimethylacetamide with acrylonitrile in the presence of sodium acetate and toluene, and then the solid thus obtained was reacted with hydrochloric acid in 2-propanol in the presence of ethanol and diisopropyl ether. U.S. patent no. 7,956,063 described a polymorphic Form A, Form B, Form C and Form D of rilpivirine hydrochloride. An unpublished application, IN 1415/CHE/201 1 assigned to Hetero Research Foundation discloses a process for the preparation of rilpivirine. According to the application, rilpivirine can be prepared by reacting the 4-(4-chloropyrimidin-2- ylamino)benzonitrile with (E)-3-(4-amino-3,5-dimethylphenyl)acrylonitrile hydrochloride in the presence of p-toluene sulfonic acid monohydrate and 1 ,4-dioxane. It has been found that the rilpivirine produced according to the prior art procedures results in low yields.

The synthesis is as follows:

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more info………………………..

Rilpivirine, which is chemically known as 4-{[4-({4-[(lE)-2-cyanoethenyl]-2,6- dimethylphenyl} amino) pyrimidin-2-yl]amino}benzonitrile, is a non-nucleoside reverse transcriptase inhibitor (NNRTI) and exhibits human immunodeficiency virus (HIV) replication inhibiting properties. Rilpivirine is used as its hydrochloride salt in the anti-HIV formulations.

Conventionally, various processes followed for the synthesis of Rilpivirine hydrochloride (I), generally involve preparation of the key intermediate, (E)-4-(2- cyanoemenyl)-2,6-dimethylphenylamine hydrochloride of formula (II).

(E)-4-(2-cyanoethenyl)-2,6-dimethylphenylamine hydrochloride (II)

WO 03/016306 first disclosed the synthesis of Rilpivirine involving different routes for synthesis of 4-(2-cyanoethenyl)-2,6-dimethylphenylamine. The first route involved protection of the amino group of 4-bromo-2,6-dimemylphenylarnine by converting to Ν,Ν-dimethylmethanimidamide, followed by formylation involving n- butyl lithium and dimethylformamide. The resulting formyl derivative was treated with diethyl(cyanomethyl) phosphonate to give the cyanoethenyl compound which was deprotected using zinc chloride to yield the cyanoethenylphenylamine intermediate having an undisclosed E/Z ratio. This route involved an elaborate sequence of synthesis comprising protection of amine by its conversion into imide, use of a highly moisture sensitive and pyrophoric base such as butyl lithium and a low yielding formylation reaction. All these factors made the process highly unviable on industrial scale.

The second route disclosed in WO 03/016306 employed 4-iodo-2,6- dimethylphenylamine as a starting material for synthesis of cyanoemenylphenylamine intermediate, which involved reaction of the dimethylphenylamine derivative with acrylonitrile for atleast 12 hours at 130 C in presence of sodium acetate and a heterogeneous catalyst such as palladium on carbon. Isolation of the desired compound involved solvent treatment with multiple solvents followed by evaporation. This route also does not give any details of the E/Z ratio of the unsaturated intermediate product. Although this route avoids use of phosphine ligands but lengthy reaction time and problem of availability of pure halo-phenylamine derivatives coupled with moderate yields hampers the commercial usefulness of this route.

The third route disclosed in WO 03/016306 involved reaction of 4-bromo-2,6- dimethylphenylamine with acrylamide in presence of palladium acetate, tris(2- methylphenyl)phosphine and N,N-diethylethanamine. The resulting amide was dehydrated using phosphoryl chloride to give 4-(2-cyanoethenyi)-2,6- dimethylphenylamine in a moderate yield of 67% without mentioning the E/Z ratio. Although the E/Z isomer ratio for the cyanoethenyl derivative obtained from these routes is not specifically disclosed in the patent, however, reproducibility of the abovementioned reactions were found to provide an E/Z ratio between 70/30 and 80/20. Various other methods have also been reported in the literature for introduction of the ‘ cyanoethenyl group in Rilpivirine. The Journal of Medicinal Chemistry (2005), 48, 2072-79 discloses Wittig or Wadsworth-Emmons reaction of the corresponding aldehyde with cyanomethyl triphenylphosphonium chloride to provide a product having an E/Z isomer ratio of 80/20. An alternate method of Heck reaction comprising reaction of aryl bromide with acrylonitrile in presence of tri-o- tolylphosphine and palladium acetate gave the same compound with a higher E/Z isomer ratio of 90/10. The method required further purification in view of the presence of a significant proportion of the Z isomer in the unsaturated intermediate. A similar method was disclosed in Organic Process Research and Development (2008), 12, 530-536. However, the E/Z ratio of 4-(2-cyanoethenyl)-2,6- dimethylphenylamine was found to be 80/20, which was found to improve to 98/2 (E/Z) after the compound was converted to its hydrochloride salt utilizing ethanol and isopropanol mixture.

It would be evident from the foregoing that prior art methods are associated with the following drawbacks:

a) High proportion of Z isomer, which requires elaborate purification by utilizing column chromatographic techniques, crystallization, or successive treatment with multiple solvents, which decreases the overall yield,

b) Introduction of cyanoethenyl group to the formylated benzenamine derivatives involves a moisture sensitive reagent like n-butyl lithium, which is not preferred on industrial scale. Further, the method utilizes cyanomethyl phosphonate esters and is silent about the proportion of the Z isomer and the higher percentage of impurities which requires elaborate purification and ultimately lowers the yield,

c) Prior art routes involve use of phosphine ligands which are expensive, environmentally toxic for large scale operations,

d) Prior art methods utilize phase transfer catalysts such as tetrabutyl ammonium bromide in stoichiometric amounts and the reactions are carried out at very high temperatures of upto 140-150°C.

Thus, there is a need to develop an improved, convenient and cost effective process for preparation of (E)-4-(2-cyanoethenyl)-2,6-dimethylphenylamine hydrochloride of formula (II) having Z-isomer less than 0.5%, without involving any purification and does not involve use of phosphine reagent and which subsequently provides Rilpivirine hydrochloride (I) conforming to regulatory specifications.

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http://www.google.com/patents/EP2643294A2?cl=en

The present inventors have developed a process for stereoselective synthesis of the key Rilpivirine intermediate, (E)-4-(2-cyanoethenyl)-2,6-dimemylphenylarnine hydrochloride (II), comprising diazotization of 2,6-dimethyl-4-amino-l- carboxybenzyl phenylamine followed by treatment with alkali tetrafluoroborate to provide the tetrafluoroborate salt of the diazonium ion which is followed by reaction with acrylonitrile in presence of palladium (II) acetate and subsequent deprotection of the amino group with an acid followed by treatment with hydrochloric acid to give the desired E isomer of compound (II) having Z isomer content less than 0.5% and with a yield of 75-80%. The compound (II) was subsequently converted to Rilpivirine hydrochloride of formula (I) with Z isomer content less than 0.1%.

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Chemical structures of selected NNRTIs

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http://pubs.acs.org/doi/full/10.1021/jm040840e

Flibanserin, girosa
167933-07-5 cas no

147359-76-0 (monoHCl)

C20-H21-F3-N4-O, 390.412, Boehringer Ingelheim (Originator)

Raleigh, N.C., December 11, 2013 – Sprout Pharmaceuticals today announced that it has received and appealed the Food and Drug Administration’s (FDA) Complete Response Letter (CRL) for flibanserin through the Formal Dispute Resolution process. Flibanserin is an investigational, once-daily treatment for Hypoactive Sexual Desire Disorder, or HSDD, in premenopausal women. HSDD is the most commonly reported form of female sexual dysfunction

read all here

A new drug being developed by Boehringer Ingelheim could give a boost to the sex drive of women with low libido. The drug, known as flibanserin, has been shown in clinical trials to increase their sexual desire when taken once a day at bedtime.

The results from four pivotal Phase III clinical trials on women with hypoactive sexual desire disorder (HSDD) were presented this week at the European Society for Sexual Medicine’s congress in Lyon, France. The trials showed that participants taking flibanserin had a significant improvement in their sexual desire compared to those given a placebo. They also experienced less of the distress associated with sexual dysfunction.

The drug was initially being investigated as a treatment for depression, and acts on the serotonin receptors in the brain – it is both a 5-HT1A receptor agonist and a 5-HT2A receptor antagonist. It is also a partial agonist at the dopamine D4 receptor.

Neurotransmitters such as serotonin are believed to be involved in sexual function, and antidepressants are commonly associated with a loss of libido, so this was an obvious side-effect to look out for during clinical trials in depression. But far from suppressing the libido in women, it appeared to have the opposite effect, so trials in women with HSDD were initiated.

Hormone replacement can improve the libido of women who have had their ovaries removed, but there is no available drug to treat those who have not. There have been accusations that pharma companies invent new diseases like HSDD in order to sell more medicines, but according to Kathleen Segraves, an assistant professor at Case Western Reserve University in the US who has worked in the field of sexual functioning for many years, this is not the case here. HSDD is a very real disorder, she says, and the potential for a treatment for these women is very exciting.

Flibanserin (code name BIMT-17; proposed trade name Girosa) is a drug that was investigated by Boehringer Ingelheim as a novel, non-hormonal treatment for pre-menopausal women with Hypoactive Sexual Desire Disorder (HSDD).^[1][2] Development was terminated in October 2010 following a negative report by the U.S. Food and Drug Administration.^[3]

HSDD is the most commonly reported female sexual complaint and characterized by a decrease in sexual desire that causes marked personal distress and/or personal difficulties. According to prevalence studies about 1 in 10 women reported low sexual desire with associated distress, which may be HSDD.^[4] The neurobiological pathway of female sexual desire involves interactions among multiple neurotransmitters, sex hormones and various psychosocial factors. Sexual desire is modulated in distinct brain areas by a balance between inhibitory and excitatory neurotransmitters, serotonin acting as an inhibitor while dopamine and norepinephrine act as a stimulator of sexual desire.^[5][6]Flibanserin is a 5-HT1A receptor agonist and 5-HT2A receptor antagonist that had initially been investigated as an antidepressant. Preclinical evidence suggested that flibanserin targets these receptors preferentially in selective brain areas and helps to restore a balance between these inhibitory and excitatory effects.^[6] HSDD has been recognized as a distinct sexual function disorder for more than 30 years.

The proposed mechanism of action refers back to the Kinsey dual control model. Several sex steroids, neurotransmitters, and hormones have important excitatory or inhibitory effects on the sexual response. Among the neurotransmitters, the excitatory activity is driven by dopamine and norepinephrine, while the inhibitory activity is driven by serotonin. The balance between these systems is relevant for a healthy sexual response. By modulating these neurotransmitters in selective brain areas, flibanserin, a 5-HT1A receptoragonist and 5-HT2A receptor antagonist, is likely to restore the balance between these neurotransmitter systems.^[6]

Several large pivotal Phase III studies with Flibanserin were conducted in the USA, Canada and Europe. They involved more than 5,000 pre-menopausal women with generalized acquired Hypoactive Sexual Desire Disorder (HSDD). The results of the Phase III North American Trials demonstrated that

Although the two North American trials that used the flibanserin 100 mg qhs dose showed a statistically significant difference between flibanserin and placebo for the endpoint of [satisfying sexual events], they both failed to demonstrate a statistically significant improvement on the co-primary endpoint of sexual desire. Therefore, neither study met the agreed-upon criteria for success in establishing the efficacy of flibanserin for the treatment of [Hypoactive Sexual Desire Disorder].

These data were first presented on November 16, 2009 at the congress of the European Society for Sexual Medicine in Lyon, France. The women receiving Flibanserin reported that the average number of times they had “satisfying sexual events” rose from 2.8 to 4.5 times a month. However, women receiving placebo reported also an increase of “satisfying sexual events” from 2.7 to 3.7 times a month. Evaluation of the overall improvement of their condition and whether the benefit was meaningful to the women, showed a significantly higher rate of a meaningful benefit in the flibanserin-treated patient group versus the placebo group.The onset of the Flibanserin effect was seen from the first timepoint measured after 4 weeks of treatment and maintained throughout the treatment period.The overall incidence of adverse events among women taking flibanserin was low, the majority of adverse events being mild to moderate and resolved during the treatment. The most commonly reported adverse events included dizziness, nausea, fatigue, somnolence and insomnia.

On June 18, 2010, a federal advisory panel to the U.S. Food and Drug Administration (FDA) unanimously voted against recommending approval of Flibanserin. Earlier in the week, a FDA staff report also recommended non-approval of the drug. While the FDA still might approve Flibanserin, in the past, negative panel votes tended to cause the FDA not to approve.

On October 8, 2010, Boehringer Ingelheim announced that it would discontinue its development of flibanserin in light of the FDA advisory panel’s recommendation.

On June 27, 2013, Sprout Pharmaceuticals confirmed they had resubmitted flibanserin for FDA approval.

• Yves Aubert, Thesis, Leiden University. (Dec 11, 2012) Sex, aggression and pair-bond: a study on the serotonergic regulation of female sexual function in the marmoset monkey
• Viagra for women?
• Marazziti D, Palego L, Giromella A, et al. (June 2002). “Region-dependent effects of flibanserin and buspirone on adenylyl cyclase activity in the human brain”. Int. J. Neuropsychopharmacol. 5 (2): 131–40. doi:10.1017/S1461145702002869.PMID 12135537.
• Podhorna J, Brown RE (June 2000). “Flibanserin has anxiolytic effects without locomotor side effects in the infant rat ultrasonic vocalization model of anxiety”. Br J Pharmacol 130 (4): 739–746. doi:10.1038/sj.bjp.0703364. PMC 1572126.PMID 10864879.
• Brambilla A, Baschirotto A, Grippa N, Borsini F (December 1999). “Effect of flibanserin (BIMT 17), fluoxetine, 8-OH-DPAT and buspirone on serotonin synthesis in rat brain”. Eur Neuropsychopharmacol 10 (1): 63–7. doi:10.1016/S0924-977X(99)00056-5.PMID 10647099.

The compound 1-[2-(4-(3-trifluoromethyl-phenyl)piperazin-1-yl)ethyl]-2,3-dihydro-1 H- benzimidazol-2-one (flibanserin) is disclosed in form of its hydrochlorid in European Patent Application EP-A-526434 and has the following chemical structure:

Flibanserin shows affinity for the 5-HTι_A and 5-HT₂-receptor. It is therefore a promising therapeutic agent for the treatment of a variety of diseases, for instance depression, schizophrenia, Parkinson, anxiety, sleep disturbances, sexual and mental disorders and age associated memory impairment.

EXAMPLE

375 kg of 1-[(3-trifluoromethyl)phenyl]-4-(2-cloroethyl)piperazin are charged in a reactor with 2500 kg of water and 200 kg of aqueous Sodium Hydroxide 45%. Under stirring 169.2 kg of 1-(2-propenyl)-1,3-dihydro-benzimidazol-2H-one, 780 kg of isopropanol, 2000 kg of water and 220 kg of aqueous Sodium Hydroxide 45% are added. The reaction mixture is heated to 75-85° C. and 160 kg of concentrated hydrochloric acid and 200 kg of water are added. The reaction mixture is stirred at constant temperature for about 45 minutes. After distillation of a mixture of water and Isopropanol (about 3000 kg) the remaining residue is cooled to about 65-75° C. and the pH is adjusted to 6.5-7.5 by addition of 125 kg of aqueous Sodium Hydroxide 45%. After cooling to a temperature of 45-50° C., the pH value is adjusted to 8-9 by addition of about 4 kg of aqueous Sodium Hydroxide 45%. Subsequently the mixture is cooled to 30-35° C. and centrifuged. The residue thus obtained is washed with 340 l of water and 126 l of isopropanol and then with water until chlorides elimination. The wet product is dried under vacuum at a temperature of about 45-55° C. which leads to 358 kg of crude flibanserin polymorph A. The crude product thus obtained is loaded in a reactor with 1750 kg of Acetone and the resulting mixture is heated under stirring until reflux. The obtained solution is filtered and the filtrate is concentrated by distillation. The temperature is maintained for about 1 hour 0-5° C., then the precipitate solid is isolated by filtration and dried at 55° C. for at least 12 hours.

The final yield is 280 kg of pure flibanserin polymorph A.

Flibanserin may be prepared by reacting 1-(phenylvinyl)-2,3-dihydro-1H-benzimidazol-2-one (I) with 1,2-dichloroethane (II) in the presence of NaH in warm dimethylformamide. The resulting 1-(2-chloroethyl)-2,3-dihydro-1H-benzimidazol-one (III) is in turn coupled with commercially available m-trifluoromethylphenylpiperazine hydrochloride (IV) in the presence of sodium carbonate and catalytic potassium iodide in refluxing ethanol. The crude flibanserin hydrochloride (V) is then dissolved in aqueous ethanol and the pure base is precipitated upon addition of sodium hydroxide.

…………………………

Journal of Pharmaceutical and Biomedical Analysis, v.57, 2012 Jan 5, p.104(5)

Isolation and structural elucidation of flibanserin as an adulterant in a health supplement used for female sexual performance enhancement

Low, Min-Yong et al

http://www.sciencedirect.com/science/article/pii/S0731708511004833

This proposed formula and structure was further confirmed by 1
H and 13C NMR data which indicated the presence of 20 carbon atoms and 21 protons.

proton nmr

13 c nmr

1D and 2DNMR data were used to assign the protons and carbon atoms.

In the1H NMR spectrum , a sharp singlet at 10.00 ppm integrating for one
proton is a typical proton attached to nitrogen. HMBC correlated this proton to C-2, C-4, and C-9 suggesting that it was H-3.

Complex signals were observedbetween 7.00 to 7.31 ppm, integrating for eight protons. A triplet at 7.31 ppm,integrating for a proton has a coupling constant of 8.0 Hz. HMBC correlated thisproton with C-16, C-19, and C-21 suggesting that it was H-20.

A double-doubletsplitting pattern at chemical shift 7.11 ppm, integrating for a proton, has couplingconstants of 6.3 Hz and 1.6 Hz.

HMBC correlated this proton to C-6, C-7, and C-9 showing that it was H-8. Overlapped signals were observed from 7.04 ppm to7.10 ppm, integrating for five protons. A double-doublet splitting pattern at 7.01ppm with coupling constant 8.0 Hz and 2.0 Hz, integrating for a proton was
observed.

HMBC correlated this proton to C-17 suggesting that it was either H-19or H-21. Four triplet signals were also observed from 2.73 ppm to 4.08 ppm,integrating for a total of twelve protons.

Two of these triplet signals at 2.74 ppmand 3.22 ppm integrated for four protons each, suggesting overlapping signals ofmethylene protons. This was further confirmed by 13C and DEPT NMR.

13C and DEPT NMR data showed the signals of four methylene, eight methineand six quaternary carbon atoms. The DEPT signals at 53.1 ppm and 48.6 ppmhave intensities which were double of those from the rest of the methylene carbonsignals, suggesting two methylene carbon atoms each contributing to the signal at 53.1 ppm and 48.6 ppm.

HMQC results further indicated that these two methylene carbon signals at 53.1 ppm and 48.6 ppm were correlated to the protons signal at 2.73 ppm and 4.08 ppm respectively, which corresponded to four protons each. The finding confirmed overlapping methylene carbon signals (at 53.1 ppm and 48.6 ppm) and methylene proton signals (at 2.73 ppm and 4.08 ppm). Hence, the unknown compound has six methylene carbon atoms with a total of twelve methylene protons.

The chemical shifts of the twelve methylene protons suggested that they were attached to relatively electronegative atoms. It was speculated that the six methylene groups were attached to the nitrogen atoms and the electron withdrawing effect of these electronegative nitrogen atoms resulted in the deshielding of the protons. HMBC and COSY correlations were used to assign the rest of the protons

The 13C NMR data  showed that there were two quaternary carbon at
155.6 ppm and 151.3 ppm. The carbon with chemical shift 155.6 ppm was C-2. Inthe structure of imidazolone, carbonyl carbon C-2 was attached to two nitrogenatoms which helped to withdraw electrons from oxygen to C-2. Hence, C-2 wasless deshielded as compared to a normal carbonyl carbon which has chemical shiftabove 170 ppm.

Eight methine carbons and two quaternary carbons with chemicalshifts above 108 ppm suggested the presence of two aromatic rings. Thequaternary carbon with chemical shift 125.4 ppm was C-22 which was attached tothree fluorine atoms. Due to the strong electron withdrawing effect of the fluorineatoms, C-22 was highly deshielded and had a high chemical shift.

The IR spectrum of the isolated compound showed absorption bands of amide (νC=O 1685 cm-1, νN-H (stretch) 3180 cm-1, νN-H (bending) 1610 cm-1), alkyl fluoride (νC-F1077 cm-1, 1112 cm-1, 1158 cm-1), aromatic ring (ν Ar-H 3028 cm-1, 3078 cm-1 andνC=C 1401 cm-1, 1446 cm-1, 1453 cm-1, 1468 cm-1, 1487 cm-1) and alkane (νC-H2891 cm-1, 2930 cm-1 2948 cm-).

The IR spectrum supported the structure of
flibanserin.

……………………………….

US5576318, 1996

¹ H NMR (DMSO-d₆ /CDCL₃ 5:2) 11.09 (b, 1H), 11.04 (s, 1H), 7.5-6.9 (SH), 4.36 (t, 2H), 4.1-3.1 (10 H)

LY335979, RS-33295-198  (Zosuquidar)

Roche Palo Alto (Originator)

LY335979 (Zosuquidar) is a selective Pgp (P-glycoprotein) inhibitor with a Ki of 59 nM. LY335979 significantly enhanced the survival of mice implanted with Pgp-expressing murine leukemia (P388/ADR) when administered in combination with either daunorubicin, doxorubicin or etoposide.

LY335979 (Zosuquidar)

M.Wt: 636.99

Formula: C₃₂H₃₁F₂N₃O₂.3HCl

Name: Zosuquidar trihydrochloride

 Elemental Analysis: C, 60.34; H, 5.38; Cl, 16.70; F, 5.97; N, 6.60; O, 5.02

CAS : 167465-36-3

167354-41-8 (free base)

Roche Bioscience (Originator), Eli Lilly and Company (Licensee).

US5654304, WO1994024107A1, WO2000075121, US6570016

Drug Des Discov 1992, 9(1): 69, Bioorg Med Chem Lett 1995, 5(21): 2473, Drugs Fut 2003, 28(2): 125

Zosuquidar is currently under development. It is now in “Phase 3″ of clinical tests in the United States. Its action mechanism consists of the inhibition of P-glycoproteins; other drugs with this mechanism include tariquidar and laniquidar. P-glycoproteins are proteins which convert the energy derived from the hydrolysis of ATP to structural changes in protein molecules, in order to perform coupling, thus discharging medicine from cells. If P-glycoprotein coded with the MDR1 gene manifests itself in cancer cells, it discharges much of the antineoplastic drugs from the cells, making cancer cells medicine tolerant, and rendering antineoplastic drugs ineffective. This protein also manifests itself in normal organs not affected by the cancer (such as the liver, small intestine, and skin cells in blood vessels of the brain), and participates in the transportation of medicine. The compound Zosuquidar inhibits this P-glycoprotein, causing the cancer cells to lose their medicine tolerance, and making antineoplastic drugs effective

Clinicial trials: Clinical report published in 2010 showed that  zosuquidar did not improve outcome in older acute myeloid leukemia, in part, because of the presence P-gp independent mechanisms of resistance. (Blood. 2010 Nov 18;116(20):4077-85.)

Zosuquidar  is a potent P-glycoprotein inhibitor, which binds with high affinity to P-glycoprotein and inhibits P-glycoprotein-mediated multidrug resistance (MDR). P-glycoprotein, encoded by the MDR-1 gene, is a member of the ATP-binding cassette superfamily of transmembrane transporters and prevents the intracellular accumulation of many natural product-derived cytotoxic agents

Zosuquidar

U.S. Patent No. 5,112,817 to Fukazawa et al. discloses certain quinoline derivatives useful as anticancer drug potentiators for the treatment of multidrug resistance. One of the initially promising active agents there-disclosed is MS-073, which has the following structure:

MS-073

U.S. Pat. Nos. 5,643,909 and 5,654,304 disclose a series of 10,11- methanobenzosuberane derivatives useful in enhancing the efficacy of existing cancer chemotherapeutics and for treating multidrug resistance. One such derivative having good activity, oral bioavailability, and stability, is zosuquidar, a compound of formula (2R)-anti-5-

3 – [4-( 10, 11 -difluoromethanodibenzosuber-5-yl)piperazin- 1 -yl]-2-hydroxypropoxy) quinoline.

Zosuquidar

Given the limitations of previous generations of MDR modulators, three preclinical critical success factors were identified and met for zosuquidar: 1) it is a potent inhibitor of P-glycoprotein; 2) it is selective for P-glycoprotein; and 3) no pharmacokinetic interaction with co-administered chemotherapy is observed.

Zosuquidar is extremely potent in vitro (Kj = 59 nM) and is among the most active modulators of P-gp-associated resistance described to date. Zosuquidar has also demonstrated good in vivo activity in preclinical animal studies. In addition, the compound does not appear to be a substrate for P-gp efflux, resulting in a relatively long duration of reversal activity in resistant cells even after the modulator has been withdrawn.

Another significant attribute of zosuquidar as an MDR modulator is the minimal pharmacokinetic (PK) interactions with several oncolytics tested in preclinical models. Such minimal PK interaction permits normal doses of oncolytics to be administered and also a more straightforward interpretation of the clinical results.

Zosuquidar is generally administered in the form of the trihydrochloride salt. Conventional zosuquidar trihydrochloride formulations include those containing zosuquidar (50 mg as free base), glycine (15 mg), and mannitol (200 mg) dissolved in enough water for injection, to yield a free base concentration of 5 mg/mL. The formulation is filled into vials and lyophilized to give a vial containing 50 mg of free base. For such formulations, a 30 mL vial size is necessary to contain 50 mg of thezosuquidar formulation. For a typical >200 mg dose of zosuquidar, multiple 50 mg vials are needed to contain the formulation, greatly increasing manufacturing costs and reducing convenience for the end user {e.g., a pharmacist). Modified Cyclodextrins

Cyclodextrins are cyclic oligomers of glucose; these compounds form inclusion complexes with any drug whose molecule can fit into the lipophile-seeking cavities of the cyclodextrin molecule. See U.S. Pat. No. 4,727,064 for a description of various cyclodextrin derivatives. Cyclodextrins of preferred embodiments can include α-, β-, and χ-cyclodextrins. The α-cyclodextrins include six glucopyranose units, the β- cyclodextrins include seven glucopyranose units, and the χ-cyclodextrins include eight glucopyranose units. The β -cyclodextrins are generally preferred as having a suitable cavity size for zosuquidar. Cyclodextrin can be in any suitable form, including amorphous and crystalline forms, with the amorphous form generally preferred. Cyclodextrins suitable for use in the formulations of preferred embodiments include the hydroxypropyl, hydroxyethyl, glucosyl, maltosyl, and maltotrosyl derivatives of β- cyclodextrin, carboxyamidomethyl-β-cyclodextrin, carboxymethyl-β-cyclodextrin, and diethylamino-β-cyclodextrin.

Pharmaceutical complexes including various cyclodextrins and cyclodextrin derivatives are disclosed in the following United States patents: U.S. Pat. No. 4,024,223; U.S. Pat. No. 4,228,160; U.S. Pat. No. 4,232,009; U.S. Pat. No. 4,351,846; U.S. Pat. No. 4,352,793; U.S. Pat. No. 4,383,992; U.S. Pat. No. 4,407,795; U.S. Pat. No. 4,424,209; U.S. Pat. No. 4,425,336; U.S. Pat. No. 4,438,106; U.S. Pat. No. 4,474,881; U.S. Pat. No. 4,478,995; U.S. Pat. No. 4,479,944; U.S. Pat. No. 4,479,966; U.S. Pat. No. 4,497,803; U.S. Pat. No. 4,499,085; U.S. Pat. No. 4,524,068; U.S. Pat. No. 4,555,504; U.S. Pat. No. 4,565,807; U.S. Pat. No. 4,575,548; U.S. Pat. No. 4,598,070; U.S. Pat. No. 4,603,123; U.S. Pat. No. 4,608,366; U.S. Pat. No. 4,659,696; U.S. Pat. No. 4,623,641; U.S. Pat No. 4,663,316; U.S. Pat. No. 4,675,395; U.S. Pat. No. 4,728,509; U.S. Pat. No. 4,728,510; and U.S. Pat. No. 4,751,095.

Chemically modified and substituted α-, β-, and χ-cyclodextrins are generally preferred over unmodified α-, β-, and χ-cyclodextrins due to improved toxicity and solubility properties. The degree of substitution of the hydroxy 1 groups of the glucopyranose units of the cyclodextrin ring can affect solubility. In general, a higher average degree of substitution of substituent groups in the cyclodextrin molecule yields a cyclodextrin of higher solubility.

Examples for Pgp inhibitors are cyclosporine A, valpodar, elacridar, tariquidar, zosuquidar, laniquidar, biricodar, S-9788, MS-209, BIBW-22 (BIBW-22-BS) , toremifene, verapamil, dexverapamil , quinine, quinidine, trans- flupentixol, chinchonine and others (J. Roberts, C. Jarry (2003) : J. Med. Chem. 46, 4805 – 4817) . The list of inhibitors of P-glycoprotein is increasing (e.g. Wang et al . (2002) : Bioorg. Med. Chem. Lett. 12, 571 – 574) .

Figure 2: Structures of BIBW-22, MS-209 and S-9788

……………………

U.S. Pat. Nos. 5,643,909 and 5,654,304, incorporated herein by reference, disclose a series of 10,11-methanobenzosuberane derivatives useful in enhancing the efficacy of existing cancer chemotherapeutics and for treating multidrug resistance. (2R)-anti-5-{3-[4-(10,11-difluoromethanodibenzosuber-5-yl)piperazin-1-yl]-2-hydroxypropoxy}quinoline trihydrochloride disclosed therein, is currently under development as a pharmaceutical agent.

U.S. pat. No. 5,654,304 (’304), incorporated by reference herein, discloses a series of 10,11-(optionally substituted)methanodibenzosuberane derivatives useful in enhancing, the efficacy of existing cancer chemotherapeutics and for treating multidrug resistance. (2R)-anti-5-{3-[4-(10,11-Difluoromethanodibenzosuber-5-yl)piperazin-1-yl]-2-hydroxypropoxy}quinolone trihydrochloride is disclosed in ’304 and is currently under development as a pharmaceutical agent. WO00/75121 discloses Form I, a crystalline form of (2R)-anti-5-{3-[4-(10,11-difluoromethanodibenzosuber-5-yl)piperazin-1-yl]-2-hydroxypropoxy}quinolone trihydrochloride.

The art disclosed in U.S. Pat. No. 5,776,939, and U.S. Pat. No. 5,643,909 both incorporated herein by reference, and PCT Patent Applications (Publication numbers WO 94/24107 and 98/22112) teach the use of 1-formylpiperazine to introduce the piperazine group of the compound of formula II

Compound II is a mixture of syn isomer (III)

and anti isomer (IV)

The process as disclosed in U.S. Pat. Nos. 5,643,909 and 5,654,304 (represented by scheme A, below) involves (a) chromatographic separation(s) of the formyl piperazine compound; and (b) deformylation of the formyl piperazine compound to provide compound IV.https://www.google.co.in/patents/US6570016?cl=en

The process of the present invention uses piperazine to react with the (1aα,6α,10bα)-6-halo-1,1-difluoro-1,1a,6,10b-tetrahydrodibenzo[a,e]cyclopropa[c]-cycloheptene compound or derivative, instead of formylpiperazine.

The process of the present invention is advantageous because piperazine is readily available in commercial quantities whereas 1-formylpiperazine, which was utilized in the process disclosed in U.S. Pat. No. 5,643,909 is often not readily available in commercial quantities. Additionally piperazine enjoys a significant cost advantage over 1-formylpiperazine.

The use of piperazine instead of 1-formylpiperazine is a significant advancement over the prior art because it obviates the need to deformylate or hydrolyze off the formyl group (step 6, scheme A), thereby providing fewer operational steps. U.S. Pat. No. 5,643,909 teaches the separation of the 1-formylpiperazine compounds by chromatography or repeated crystallization. The present invention obviates the need for chromatographic separations of the formylpiperazine diastereomeric addition compounds (see step 4, scheme A)

EXAMPLES

The following examples and preparations are illustrative only and are not intended to limit the scope of the invention in any way.

Preparation 1 R-1-(5-Quinolinyloxy)-2,3-epoxypropane

A mixture of 5-hydroxyquinoline (5.60 g, 38.6 mmol), R-glycidyl nosylate (10.0 g, 38.6 mmol), powdered potassium carbonate (11.7 g, 84.9 mmol), and N,N-dimethylformamide (100 mL) was stirred at ambient temperature until HPLC analysis (40% acetonitrile/60% of a 0.5% aqueous ammonium acetate solution, 1 mL/min, wavelength=230 nm, Zorbax RX-C8 25 cm×4.6 mm column) indicated complete disappearance of glycidyl nosylate (approximately 6 hours). The reaction mixture was filtered through paper and the filter cake was washed with 200 mL of a 3:1 mixture of MTBE and methylene chloride. The filtrate was washed with 200 mL of water and the aqueous layer was extracted four times with 100 mL of 3:1 MTBE/methylene chloride. The combined organic layers were dried over 30 grams of magnesium sulfate and the dried solution was then stirred with 50 grams of basic alumina for 30 minutes. The alumina was removed by filtration and the filter cake was washed with 200 mL of 3:1 MTBE/methylene chloride. The filtrate was concentrated to a volume of 100 mL, 300 mL of MTBE were added, and the solution was again concentrated to 80 mL. After heating to 50° C., the solution was treated with 160 mL of heptane dropwise over 15 minutes, allowed to cool to 40° C., and seeded, causing the formation of a crystalline precipitate. The mixture was stirred for two hours at ambient temperature and then at 0-5° C. for an additional 2 hours. The crystals were filtered, washed with cold heptane, and dried to provide 5.68 g (73.2%) of (2R)-1-(5-quinolinyloxy)-2,3-epoxypropane as white needles.

mp 79-81° C.;

[α]²⁵ _D−36.4° (c 2.1, EtOH);

¹H NMR (500 MHz, CDCl₃)δ 2.83 (dd, J=4.8, 2.7 Hz, 1H), 2.97 (m, 1H), 3.48 (m, 1H), 4.10 (dd, J=11.0, 6.0 Hz, 1H), 4.43 (dd, J=11.0, 2.7 Hz, 1H), 6.85 (d, J=7.8 Hz, 1H), 7.38 (dd, J=8.5 Hz, 4.1 Hz, 1H), 7.59 (m, 1H), 7.71 (d, J=8.5 Hz, 1H), 8.61 (m, 1H), 8.90 (m, 1H).

Example 1 (2R)-Anti-1-[4-(10,11-difluoromethano-10,11-dihydro-5H-dibenzo[a,d]cyclohepten-5-yl)-piperazin-1-yl]-3-qunolin-5-yloxy)-propan-2-ol Trihydrochloride

Preparation of the above compound is exemplified in the following preparative steps.

Step 1 1,1-Difluoro-1a,10b-dihydrodibenzo[a,e]cyclopropa[c]-cyclohepten-6 (1H)-one

A solution of sodium chlorodifluoroacetate (350 g) in diglyme (1400 mL) was added dropwise over 4 to 8 hours, preferably over 6 hours, to a solution of 5H-dibenzo[a,d]cyclo-hepten-5-one (25 g) in diglyme (500 mL), with stirring, and under nitrogen, maintaining the reaction temperature at 160°-165° C. The cooled reaction mixture was poured into water (1.8 L) and extracted with ether (1.8 L). The organic phase was washed with water, dried over sodium sulfate (Na₂SO₄), and evaporated. The residue was recrystallized from ethanol, then from acetone/hexane to give 14 g of 1,1-difluoro-1a,10b-dihydrodibenzo[a,e]cyclopropa[c]-cyclohepten-6(1H)-one.

mp 149.6° C.

Flash chromatography of the combined mother liquors on silica gel, eluting with 20% acetone/hexane, gave an additional 6.5 g of the target compound.

Step 2 (1aα,6β,10bα)-1,1-Difluoro-1,1a,6,10b-tetrahydrodibenzo[a,e]cyclopropa[c]cyclohepten-6-ol

A solution of 1,1-difluoro-1a,10b-dihydro-dibenzo[a,e]cyclopropa[c]cyclohepten-6(1H)-one (20.4 g) in tetrahydrofuran/methanol (1:2, 900 mL) was cooled in an ice bath. Sodium borohydride (12 g) was added in portions. The cooling bath was removed and the reaction mixture was stirred at ambient temperature for 2 hours, then poured into water. The product was filtered off, washed with water, and dried to give 20 g of (1aα,6β,10bα)-1,1-difluoro-1,1a,6,10b-tetrahydrodibenzo[a,e]cyclopropa[c]cyclohepten-6-ol (ii).

mp 230.1°-230.6° C.

Step 2A Combined Steps 1 and 2 Procedure (1aα,6β,10bα)-1,1-Difluoro-1,1a,6,10b-tetrahydrodibenzo[a,e]cyclopropa[c]cyclohepten-6-ol

To a solution of 103.1 g (0.500 mol) of 5H-dibenzo[a,d]cyclohepten-5-one (2) in 515 mL of triethylene glycol dimethyl ether heated to between 180° C. and 210° C. was added over 7 hours, 293.3 g (2.15 mol) of chlorodifluoroacetic acid lithium salt (as a 53% by weight solution in ethylene glycol dimethyl ether). The ethylene glycol dimethyl ether was allowed to distill from the reaction as the salt addition proceeded. The GC analysis of an aliquot indicated that all of the 5H-dibenzo[a,d]cyclohepten-5-one had been consumed. The reaction was cooled to ambient temperature and then combined with 400 mL of ethyl acetate and 75 g of diatomaceous earth. The solids were removed by filtration and washed with 300 mL of ethyl acetate. The washes and filtrate were combined and the ethyl acetate was removed by concentration under vacuum leaving 635 g of dark liquid. The dark liquid was cooled to 18° C. and to this was added, over 15 minutes, 6.62 g (0.175 mol) of sodium borohydride (as a 12% by wt solution in 14 M NaOH). After stirring for 2 h the reaction was quenched by careful addition of 900 mL of a 1:3.5:4.5 solution of conc. HCl-methanol-water. The suspension was stirred for 30 min and the crude product was collected by filtration, washed with 600 mL of 1:1 methanol-water and dried to 126.4 g of dark brown solid. The crude product was slurried in 600 mL of methylene chloride, filtered, washed twice with 150 mL portions of methylene chloride, and dried to 91.6 g (71%) of (1aα,6β,10bα)-1,1-difluoro-1,1a,6,10b-tetrahydrodibenzo[a,e]cyclopropa[c]-cyclohepten-6-ol. Gas Chromatography (GC) Conditions; Column: JW Scientific DB-1, Initial Temperature 150° C. for 5 min, 10° C./min ramp, Final temp 250° C. for 5 min. t_R: intermediate, 11.5 min; reaction product (alcohol), 11.9 min; starting material, 12.3 minutes.

Step 3 Preparation of (1aα,6α,10b)-6-bromo-1,1-difluoro-1,1a,6,10b-tetrahydrodibenzo[a,e]cyclopropa-[c]cycloheptene

A slurry of (1aα,6β,10bα)-1,1-difluoro-1,1a,6,10b-tetrahydrodibenzo[a,e]cyclopropa[c]-cyclohepten-6-ol (3.0 g, 11.6 mmol, 1.0 equiv) in heptane (24 mL) was treated with 48% HBr (1.58 mL, 14.0 mmol, 1.2 equiv) and the reaction was heated at reflux with vigorous stirring for 2.5 hr. Solvent was then removed by atmospheric distillation (bp 95-98° C.) until approximately 9 mL of distillate was collected. The reaction was cooled and treated with EtOAc (15 mL), Na₂SO₄ and activated charcoal. The mixture was stirred at RT for 15 min and filtered through hyflo. The filter cake was washed with 50:50 EtOAc:heptane and the filtrate was concentrated in vacuo to provide the title product as a crystalline solid.

mp 119° C. (3.46 g corr., 93%);

¹H NMR (500 MHz CDCl₃) δ 7.20-7.41 (8H, m), 5.81 (1H, s), 3.41 (2H, d, J 12.5 Hz);

¹³CNMR (126 MHz CDCl₃) δ 141.3, 141.2, 133.5, 130.1, 129.8, 128.3, 128.2, 112.9, 110.6, 110.5, 108.3, 53.6, 30.2, 30.1, 30.0.

Anal. Calcd. For C₁₆H₁₁BrF₂: C, 59.84; H, 3.45. Found: C, 60.13; H, 3.50.

Step 3A Preparation of (1aα,6α,10bα)-6-Bromo-1-difluoro-1,1a,6,10b-tetrahydrodibenzo[a,e]cyclopropa[c]cycloheptene

To a stirred suspension of (1aα,6β,10bα)-1,1-difluoro-1,1a,6,10b-tetrahydrodibenzo[a,e]cyclopropa[c]-cyclohepten-6-ol, (18.4 g, 71.2 mmol) in 151 mL of methylene chloride which had been cooled to 10-17° C. was added phosphorous tribromide (9.6 g, 35.6 mmol) dropwise over 15 minutes. The cooling bath was removed and the reaction was stirred for 2 hours at ambient temperature. Analysis by gas chromatography indicated complete consumption of starting material. Cold water (92 mL) and activated carbon (1.84 g) were added and the resulting mixture was stirred for 30 minutes. The activated carbon was removed by filtration through Hyflo brand filter aid and the two phases were separated. The organic phase was washed with water (184 mL×2), brine (184 ml), dried over magnesium sulfate and concentrated to dryness under vacuum, affording 21.7 g (94.8%) of (1aα,6α,10bα)-6-bromo-1,1-difluoro-1,1a,6,10b-tetrahydrodibenzo[a,e]cyclopropa[c]cycloheptene.

¹H NMR (CDCl₃, 300 MHz) δ 3.36 (s, 1H), 3.40 (s, 1H), 5.77 (s, 1H), 7.16-7.38 (m, 8H).

Steps 4 and 5 (1aα,6α,10bα)-1-(1,1-Difluoro-1,1a,6,10b-tetrahydrodibenzo[a,e]cyclopropa[c]cyclohepten-6-yl)-piperazine, Hydrobromide Salt

To a solution of 237.5 g (0.739 mol) of (1aα,6α,10bα)-6-bromo-1,1-difluoro-1,1a,6,10b-tetrahydrodibenzo[a,e]-cyclopropa[c]cycloheptene in 3.56 L of acetonitrile was added 207.7 g (2.41 mol) of piperazine and the mixture was heated to reflux for 2 hours, at which time analysis by gas chromatography showed complete consumption of (1aα,6α,10bα)-6-bromo-1,1-difluoro-1,1a,6,10b-tetrahydrodibenzo[a,e]cyclopropa[c]cycloheptene (iii) and formation of a mixture of syn and anti piperazine compounds (III and IV) in an anti-syn ratio of 55:45. The reaction was cooled to about 7° C. and stirred for 30 minutes at that temperature. The reaction mixture was filtered to remove the precipitated syn-isomer (III) and the filter cake was washed with 250 mL of acetonitrile. The combined filtrate and wash were concentrated under vacuum to 262.4 grams of a foam which was dissolved in 450 mL of acetonitrile with heating. The solution was cooled to about 12° C. in an ice bath and stirred for 1 hour at that temperature. The precipitated syn-piperazine compound of formula (III) was filtered and washed with 125 ml of acetonitrile. The combined filtrate and wash were concentrated under vacuum to 194.1 g and dissolved in 1.19 L of ethyl acetate. The organic solution was washed sequentially with 500 mL portions of 1N sodium hydroxide, water, and saturated sodium chloride. The ethyl acetate solution was dried over sodium sulfate and concentrated to give 137.0 grams of residue which was dissolved in 1.37 L of methylene chloride and seeded with (1aα,6α,10bα)-1-(1,1-difluoro-1,1a,6,10b-tetrahydrodibenzo[a,e]cyclopropa[c]-cyclohepten-6-yl)-piperazine, hydrobromide salt, followed by the addition of 70.8 grams of 48% aqueous hydrobromic acid. The mixture was stirred for about 45 minutes, causing the anti-isomer to crystallize as its hydrobromide salt. The crystals were filtered, washed with methylene chloride, and dried to provide purified hydrobromide salt of compound (IVa), shown by HPLC to have an anti-syn ratio of 99.3:0.7. Treatment of the isolated hydrobromide salt of compound (IVa) with aqueous sodium hydroxide, extraction into methylene chloride, separation of the aqueous layer and concentration to dryness gave 80.1 grams (33.2% yield based on starting material) of (1aα,6α,10bα)-1-(1,1-difluoro-1,1a,6,10b-tetrahydrodibenzo[a,e]cyclopropa[c]-cyclohepten-6-yl)-piperazine as the free base. Acidification of a solution of the free base in 800 mL of methylene chloride by addition of 41.2 g of 48% hydrobromic acid as described above afforded 96.4 g of pure hydrobromide salt (title compound) with an anti-syn ratio of 99.8:0.2 (HPLC), mp 282-284° C. ¹H NMR (DMSO-d₆) δ 2.41 (m, 4H), 3.11 (m, 4H), 3.48 (d, J=12.4 Hz, 2H), 4.13 (s, 1H), 7.2 (m, 8H), 8.65 (bs, 2H). ¹³C NMR (DMSO-d₆) δ 28.0, 42.9, 48.0, 75.1, 108.5, 112.9, 117.3, 127.5, 128.0, 128.6, 129.6, 132.4, 141.3. IR: (KBr) 3019, 2481, 1587, 1497, 1298 cm⁻¹. Anal. Calcd for C₂₀H₂₁BrF₂N₂: C, 58.98; H, 5.20; N, 6.88. Found: C, 58.75; H, 5.29; N, 7.05.

Step 6 Preparation of (2R)-Anti-1-[4-(10,11-difluoromethano-10,11-dihydro-5H-dibenzo[a,d]cyclohepten-5-yl)-piperazin-1-yl]-3-quinolin-5-yloxy)propan-2-ol Trihydrochloride

A suspension of (1aα,6α,10bα)-1-(1,1-difluoro-1,1a,6,10b-tetrahydrodibenzo[a,e]cyclopropa[c]-cyclohepten-6-yl)-piperazine, hydrochloride compound of formula IVa (5.41 g, 14.9 mmol) and powdered sodium carbonate (3.16 g, 29.8 mmol) in 54 mL of 3A ethanol was stirred at ambient temperature for 1 hour. R-1-(5-quinolinyloxy)-2,3-epoxypropane (3.00 g, 14.9 mmol) was added in one portion and the reaction mixture was heated to 65° C. for 19 hours. HPLC analysis (Gradient system with solvent A (acetonitrile) and solvent B (0.02M sodium monophosphate buffer containing 0.1% triethylamine adjusted to pH 3.5 with phosphoric acid) as follows: 0-12 min, 30% solvent A/70% solvent B; 12-30 min, linear gradient from 30% to 55% solvent A/70% to 45% solvent B; 30-35 min, 55% solvent A/45% solvent B, 1 mL/min, 1=240 nm, Synchropak SCD-100 25 cm×4.6 mm column) indicated the total consumption of the piperazinyl compound of formula (IV). The mixture was allowed to cool to room temperature, filtered through a plug of silica gel, and eluted with an additional 90 mL of ethanol. The eluent was concentrated to a volume of approximately 60 mL and heated to 65° C. with stirring. A solution of HCl in ethanol (16.1 g at 0.135 g/g of solution, 59.6 mmol) was added dropwise over 10 minutes and the resultant product solution was seeded, causing the trihydrochloride salt to precipitate. The mixture was allowed to cool to ambient temperature and stirred slowly (less than 100 RPM) for 2 hours. The precipitate was filtered, washed with ethanol, and dried in vacuo at 50° C. to give the crude trihydrochloride salt which was further purified by recrystallization from methanol/ethyl acetate to provide 7.45 g (78.4%) of (2R)-anti-1-[4-(10,11-difluoromethano-10,11-dihydro-5H-dibenzo[a,d]cyclohepten-5-yl)-piperazin-1-yl]-3-quinolin-5-yloxy)-propan-2-ol trihydrochloride.

Step 6a

The syn isomer compound of formula (III) isolated as described supra (combined steps 4 and 5), can be utilized to produce the corresponding syn-5-{3-[4-(10,11-difluoromethano-dibenzosuber-5-yl)piperazin-1-yl]-2-hydroxypropoxy}quinoline trihydrochloride (XII) essentially as shown below for the free base of the anti isomer (IVa)in step 6.

https://www.google.co.in/patents/US6570016?cl=en

………………………………………

http://www.google.it/patents/WO1994024107A1?cl=en

REACTION SCHEME 1

FormuIa 1

Formula 1

Formula 2 Formula 2

Formula 3

Formula 3

Formula 4

Formula I

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http://www.google.com/patents/WO2000075121A3

¹HNMR (500 MHz DMSO-d₆) δ9.41 (2H, br. s), 7.17-7.31 (8H, m), 4.17 (1H, s), 3.52 (2H, d, J=12.4 Hz), 3.11 (4H, br. s), 2.48-2.51 (4H, m)

¹³CNMR (126 MHz DMSO-d₆) δ142.3, 133.4, 130.5, 129.6, 129.0, 128.4, 115.9, 113.6, 111.3, 76.2, 49.0, 43.6, 29.2, 29.1, 29.0; FD MS: m/e 326 (M+).

Anal. Calcd. For C₂₀H₂₁ClF₂N₂: C, 66.20; H, 5.83; N, 7.72.

Found: C, 66.08; H, 5.90; N, 7.72.

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http://www.google.com/patents/US6570016?cl=fr

(2R)-Anti-1-[4-(10,11-difluoromethano-10,11-dihydro-5H-dibenzo[a,d]cyclohepten-5-yl)-piperazin-1-yl]-3-qunolin-5-yloxy)-propan-2-ol Trihydrochloride

……………….

Chemical Shift Data and Peak Assignments for the Crystal Forms.

https://www.google.co.in/patents/US7282585?pg=PA1&dq=US+7282585&hl=en&sa=X&ei=zN64UsC2FIaSrgfS8YGIBQ&ved=0CDcQ6AEwAA

Form II has a solid-state ¹³C NMR spectrum comprised of isotropic peaks at the following chemical shifts: 29.9, 50.1, 55.3, 62.0, 66.5, 72.0, 75.8, 104.8, 107.5, 108.2, 109.1, 110.2, 112.0, 118.4, 119.5, 120.1, 123.1, 128.7, 131.1, 133.0, 134.8, 136.4, 136.9, 139.9, 140.0, 142.3, 144.5, 146.6, 149.0, 144.2, 153.0 and 153.6 ppm.

Form III has a solid-state ¹³C NMR spectrum comprised of isotropic peaks at the following chemical shifts: 30.3, 50.4, 59.1, 63.2, 72.8, 77.2, 109.1, 110.2, 112.2, 112.8, 118.7, 119.5, 119.9, 121.0, 122.2, 123.0, 128.9, 130.6, 132.7, 134.0, 136.4, 140.0, 141.0, 141.8, 142.5, 143.3, 146.1, 153.1, 153.8 and 154.7 ppm.

DARUNAVIR

206361-99-1  CAS NO

[(1S,2R)-3-[[(4-Aminophenyl)sulfonyl] (2-methylpropyl)amino]-2-hydroxy-1-(phenylmethyl)propyl]carbamic acid (3R,3aS,6aR)-hexahydrofuro[2,3-b]furan-3-yl ester

M. P.:- 72-74 °C (dec)

MW: 547.66

Darunavir and processes for its preparation are disclosed in EP0715618, W09967417, EP1725566 and Bioorganic & Medicinal Chemistry Letters (2004), 14(4), 959-963.

J Med Chem. 2013 May 23;56(10):4017-27. doi: 10.1021/jm400231v

US20050250845 discloses various pseudopolymorphs of darunavir and processes for their preparation. According to this application, “pseudopolymorph” is defined as a crystalline form of a compound in which solvent molecules are incorporated in the lattice structure. The Form B disclosed in the patent application is a pseudopolymorph wherein water is used as solvent. The thermogravimetric experiments of the Form B shows weight loss of 3.4% in the temperature range 25-78°C (water), 5.1% in the temperature range 25-1 10°C (ethanol and water) and further 1.1% weight loss (ethanol) in temperature range 110-200° C. Further at the drying step the Form B showed about 5.6% weight loss. The obtained dried product was hygroscopic and it adsorbed up to 6.8% water at high relative humidity. Amorphous form of darunavir is disclosed in US20050250845 and the publication in J.Org. Chem. 2004, 69, 7822 – 7829.

US 7700645 patent disclosed amorphous Darunavir, various solvates of Darunavir including ethanolate and method for their preparation as well as their use as a medicament. Journal of Organic Chemistry 2004, 69, 7822-7829 disclosed amorphous Darunavir is obtained by purification with column chromatography in 2% methanol in chloroform as eluent. PCT publication WO2010086844A1 disclosed crystalline dimethylsulfoxide solvate and crystalline tetrahydrofuran solvate of darunavir. The publication also disclosed the amorphous darunavir having the IR spectrum with characteristic peaks at about 1454 and 1365 cm^“1

PCT publication WO201 1083287A2 disclosed crystalline darunavir hydrate substantially free of any non aqueous solvent.

Drug information:- Darunavir is an Anti-microbial drug further classified as anti-viral agent of the class protease inhibitor. It is used either single or in combination with other drugs for the treatment of human immunodeficiency virus.

Darunavir (brand name Prezista, formerly known as TMC114) is a drug used to treat HIV infection. It is in the protease inhibitor class. Prezista is an OARAC recommended treatment option for treatment-naïve and treatment-experienced adults and adolescents.Developed by pharmaceutical company Tibotec, darunavir is named after Arun K. Ghosh, the chemist who discovered the molecule at the University of Illinois at Chicago. It was approved by the Food and Drug Administration (FDA) on June 23, 2006.^[2]

Darunavir is a second-generation protease inhibitor (PIs), designed specifically to overcome problems with the older agents in this class, such as indinavir. Early PIs often have severe side effects and drug toxicities, require a high therapeutic dose, are costly to manufacture, and show a disturbing susceptibility to drug resistant mutations. Such mutations can develop in as little as a year of use, and effectively render the drugs useless.

Darunavir was designed to form robust interactions with the protease enzyme from many strains of HIV, including strains from treatment-experienced patients with multiple resistance mutations to PIs.

Darunavir received much attention at the time of its release, as it represents an important treatment option for patients with drug-resistant HIV. Patient advocacy groups pressured developer Tibotec not to follow the previous trend of releasing new drugs at prices higher than existing drugs in the same class. Darunavir was priced to match other common PIs already in use, such as the fixed-dose combination drug lopinavir/ritonavir.

PREZISTA (darunavir) is an inhibitor of the human immunodeficiency virus (HIV-1) protease.

PREZISTA (darunavir), in the form of darunavir ethanolate, has the following chemical name: [(1S,2R)-3-[[(4-aminophenyl)sulfonyl](2-methylpropyl)amino]-2-hydroxy-1-(phenylmethyl)propyl]-carbamic acid (3R,3aS,6aR)-hexahydrofuro[2,3-b]furan-3-yl ester monoethanolate. Its molecular formula is C₂₇H₃₇N₃O₇S • C₂H₅OH and its molecular weight is 593.73. Darunavir ethanolate has the following structural formula:

Darunavir ethanolate is a white to off-white powder with a solubility of approximately 0.15 mg/mL in water at 20°C.

Virus-encoded proteases, which are essential for viral replication, are required for the processing of viral protein precursors. Interference with the processing of protein precursors inhibits the formation of infectious virions. Accordingly, inhibitors of viral proteases may be used to prevent or treat chronic and acute viral infections. Darunavir has HIV protease inhibitory activity and is particularly well suited for inhibiting HIV-I and HIV -2 viruses. Darunavir, chemically (1 S^R.S’R.S’aS.e’aRJ-fS’he ahydrofuro^.S-b ]furanyl-[3-( 4-aminobenzenesulfonyl)isobutylamino [- 1-benzyl-zhydroxypropyl]carbamate. Darunavir is represented by the following structure:

Darunavir and its pharmaceutically acceptable salts were disclosed in US 6248775 patent, wherein Darunavir is prepared by condensing 2R-hydroxy-3-[[(4-aminophenyl)sulfonyl](2- methylpropyl)amino]-1S(phenylmethyl)propylamine with hexahydro-furo[2,3-b]furan-3-ol in anhydrous acetonitrile in the presence of anhydrous pyridine and Ν,Ν’-disuccinimidyl carbonate at ambient temperature.

US 7700645 patent disclosed amorphous Darunavir, various solvates of Darunavir including ethanolate and method for their preparation as well as their use as a medicament. Journal of Organic Chemistry 2004, 69, 7822-7829 disclosed amorphous Darunavir is obtained by purification with column chromatography in 2% methanol in chloroform as eluent. PCT publication WO2010086844A1 disclosed crystalline dimethylsulfoxide solvate and crystalline tetrahydrofuran solvate of darunavir. The publication also disclosed the amorphous darunavir having the IR spectrum with characteristic peaks at about 1454 and 1365 cm^“1

PCT publication WO201 1083287A2 disclosed crystalline darunavir hydrate substantially free of any non aqueous solvent.

Darunavir Ethanolate, has the chemical name: [(1 S, 2R)-3-[[(4-aminophenyl) sulfonyl](2- methylpropyl)amino]-2-hydroxy-1-(phenylmethyl)propyl]carbamic acid (3/?, 3aS, 6a/?)- hexahydrofuro[2,3-i>]furan-3-yl ester monoethanolate and has the following structural formula:

Darunavir and its process are first disclosed in US 6248775, wherein 2 ?-hydroxy-3-[[(4- aminophenyl)sulfonyl](2-methylpropyl)amino]-1 S(phenylmethyl) propylamine (4) is reacted with (3R, 3aS, 6aR)-hexahydrofuro[2,3- >]furan-3-ol in anhydrous acetonitrile in the presence of N, W-disuccinimidyl carbonate, anhydrous pyridine at ambient temperature followed by workup to get Darunavir (Scheme A).

Scheme A

Darunavir

US 20050250845 disclosed the various solvates of Darunavir including ethanolate and method for their preparation as well as their use as a medicament. The same application disclosed the amorphous Darunavir by Raman spectra without process details.

WO 2005063770 discloses process for the preparation of Darunavir ethanolate, wherein 2R-hydroxy-3-[[(4-aminophenyl)sulfonyl](2-methylpropyl)amino]-1 S-(phenylmethyl)propyl amine (4) is reacted with (3R, 3aS, 6a ?)-hexahydrofuro[2,3-b]furan-3-ol in the presence of N, /V-disuccinimidyl carbonate, triethylamine, 41% methylamine in ethanol in a mixture of ethyl acetate and acetonitrile followed by workup and crystallization from ethanol to get Darunavir ethanolate (Scheme B).

Scheme B

In the prior art process, compound of formula 4 condensed with (3/?, 3aS, 6aR)- hexahydrofuro[2,3-6]furan-3-ol in large excess of solvent or solvent mixture containing large excess of base or mixture of bases to get Darunavir. Further, the obtained products by the processes described in the prior art are not satisfactory, from purity point of view. We have repeated the Darunavir synthetic procedures as described in the prior art and found that relatively large amounts of impurities were obtained along with Darunavir (Table-1) which need repeated crystallizations in different solvents to get desired quality of the final product resulting in poor yields. Among other impurities, the carbonic acid [(1/?,2S)-1-{((4-amino-benzenesulfonyl)-isobutyl-amino)-methyl}-2-((3R,3aS_I6aR)- hexahydro-furot2,3-/3]furan-3-yloxycarbonylamino)-3-phenyl-propylester (3R,3aS,6aR)- hexahydro-furo[2,3-ft]furan-3-yl ester (difuranyl impurity of formula 1) is identified.

Conditions:-

i. Phenyl magnesium bromide, Cuprous cyanide, tetrahydrofuran, 23 °C, 1 h,

ii. t-Butyl hydroperoxide, titanium tetraisopropoxide, diethyl D-tartrate, dichloromethane, -22 °C, 24 h,

iii. Azidotrimethylsilane, titanium tetraisopropoxide, Benzene, reflux, 25 min,

iv. 2-Acetoxyisobutyryl chloride, Chloroform, 23 °C, 8 h,

v. Isobutyl amine, isopropanol, 80 °C, 12 h,

vi 4-aminobenzenesulfonyl chloride, aq. Sodium bicarbonate, dichloromethane, 23 °C, 12 h,

vii. 10% palladium on carbon, hydrogen gas (50 psi), methanol, acetic acid, tetrahydrofuran, room temperature, 2 h,

viii. [3R, 3aS,6aS]-3-hydroxyhexahydrofuro[2,3-b]-furan, disuccanamidyl carbonate, triethylamine, acetonitrile, 23 °C, 12 h

Schematic Representation for Synthesis of Darunavir

Preparation of Darunavir is described in US patent 05,158,713, and also in WO9967417 and WO9967254. Accordingly, 2-vinyloxirane 1 on reacting with phenyl magnesium bromide in presence of tetrahydrofuran solvent and cuprous cyanide catalyst give 4-phenylbut-2-ene-1-ol 2. Oxidizing 2 with t-Butyl hydroperoxide in presence of titanium tetraisopropoxide and diethyl D-tartrate using dichloromethane as solvent give [(3S)-3-benzyloxiran-2-yl]methanol 3.

Heating 3 with azidotrimethylsilane in presence of titanium tetraisopropoxide using benzene as solvent give (2S,3S)-3-azido-4-phenyl-butane-1,2-diol 4. The 1,2-dipl compound 4 underwent cyclization when treated with 2-acetoxyisobutyryl chloride in chloroform give (2S)-2-[(1S)-1-azido-2-phenyl-ethyl]oxirane 5, which was further heating with isobutylamine and isopropanol at higher temperature give (2R,3S)-3-azido-1-(isobutylamino)-4-phenyl-butan-2-ol 6. Compound 6 was reacted with 4-aminobenzenesulfonyl chloride in presence of aq. Sodium bicarbonate as base and dichloromethane as solvent resulting in to 4-amino-N-[(2R,3S)-3-azido-2-hydroxy-4-phenyl-butyl]-N-isobutyl-benzenesulfonamide 7.

Hydrogenating 7 with 10% palladium on carbon catalyst using hydrogen gas (50 psi) in methanol and tetrahydrofuran solvent in presence of small amount of acetic acid at ambient temperature resulted in to 4-amino-N-[(2R,3S)-3-amino-2-hydroxy-4-phenyl-butyl]-N-isobutyl-benzenesulfonamide 8. The final step involves reacting 8 with [3R,3aS,6aS]-3-hydroxyhexahydrofuro[2,3-b]-furan and disuccanamidyl carbonate in presence of triethylamine base and acetonitrile as solvent afford [(1S,2R)-3-[[(4-Aminophenyl)sulfonyl] (2-methylpropyl)amino]-2-hydroxy-1-(phenylmethyl)propyl]carbamic acid (3R,3aS,6aR)-hexahydrofuro[2,3-b]furan-3-yl ester also called Darunavir 9.

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http://www.google.com/patents/WO2013114382A1?cl=en

process for the preparation of amorphous Darunavir is as

Process for the preparation of intermediate 2 is as shown in below scheme.

Examples

Example -1 : Preparation of [(1S, 2S)-3-chloro-2-hydroxy-1-(phenyl methyl) propyl] carbamic acid tert-butyl ester (5).

The solution of (3S)-3-(tert-butoxycarbonyl) amino-1-chloro-4-phenyl-2-butanone (Chloromethyl ketone 6,100 g) and aluminium isopropoxide (35 g) in isoprpylalcohol was heated to mild reflux and maintained for 3 hours. After completion of reaction distilled off isopropyl alcohol up to 50 % under vacuum and the resultant mass was cooled to 25-35°C. Water was added to the distillate, pH was adjusted to 3.0-4.0 with acetic acid and maintained the stirring for 2 hours at 25-35°C. The obtained solid was filtered and washed with water. The wet cake was taken into isopropyl alcohol (400mL) and heated to reflux for 60minutes, the mass was cooled to 25-35°C again maintain the stirring for 60minutes, the obtained solid was filtered and washed with isopropyl alcohol. The wet product was dried under normal drying to get title compound 5 (yield 80 g). Example -2: Preparation of [(1 S, 2R)-3-[(2-methylpropyl) amino]-2-hydroxy-1- (phenylmethyl) propyl] carbamic acid tert-butyl ester (4).

The mixture of [(1S, 2S)-3-chloro-2-hydroxy-1-(phenylmethyl) propyl] carbamic acid tert-butyl ester (5,100 g), isobutyl amine (294 g), sodium carbonate (31.3 g) and water was heated to 60 – 65°C and maintained for 3hours. After completion of reaction water (200 mL) was added and distilled out excess isobutyl amine under vacuum at below 75°C. Water (800 mL) was added to the distillate, cooled to 25-35°C and stirred for 2 hours. The obtained solid was filtered and washed with water to get title compound 4 (yield 105 g).

Example -3: Preparation of [(1S, 2R)-3-[[(4-nitrophenyl) sulfonyl] (2-methylpropyl) amino]- 2-hydroxy-1-(phenylmethyl) propyl] carbmic acid tert-butylester (3).

[(1 S, 2R)-3-[(2-methylpropyl) amino]-2-hydroxy-1 -(phenyl methyl) propyl] carbamic acid tert-butyl ester (4, 100 gm) and triethylamine (39.04 g) was added to methylenedichloride (1200 mL) and the temperature was raised to 40°C. p-nitro benzene sulfonyl chloride solution (72.3g of p-NBSC dissolve in 300mL methylenedichloride) was added slowly at 40-45°C for 2-3 hrs. The reaction was maintained for 3hours at 40 – 45°C. After completion of the reaction, water (500 mL) was added, separated the organic layer and distilled out methylene dichloride at atmospheric pressure. Finally, strip out the methylene dichloride by using isopropyl alcohol (200 mL). Isopropyl alcohol (1000 mL) was added to the distillate and maintained the stirring for 60 minutes at 70- 80°C. Cooled the mass to 30 – 35°C, filtered and washed with Isopropyl alcohol to get title compound 3 (yield 145 g). Example – 4: Preparation of 4-Amino-N-(2R, 3S) (3-amino-2-hydroxy-4-phenylbutyl)-N- isobutyl-benzene sulfonamide (1).

(1S, 2R)-{1-benzyl-2-hydroxy-3-[isobutyl-(4-nitro-benzenesulfonyl)-amino]-propyl}-carbamic acid tert-butyl ester (3, 100g), 10% palladium carbon (10gm) and triethanolamine (2gm) were suspended in isopropyl alcohol. The reaction was heated to 40 – 45°C and maintained under 4 – 6kg/cm2 of hydrogen pressure for 3 hours. After completion of reaction, the mass was filtered and hydrochloric acid (70mL) was added to the filtered mass. The solution was heated to reflux and maintained for 2-3hours. After completion of reaction the mass was cooled to 25-35°C, the reaction mass pH was adjusted to 6.0 – 7.0 with 20% sodium hydroxide solution and distilled out isopropyl alcohol under vacuum at below 55°C. Ethanol (200mL) and water (400mL) was added to the distillate, the mass pH was adjusted to 9.0 – 10.0 with 20% sodium hydroxide solution at 25-35°C and maintained the stirring for 2 hours at 25-35°C. The mass was cooled to 0 – 5°C, filtered and wash with water. The wet product was taken into ethanol (350mL), maintained the stirring for 30minutes at reflux temperature. The mass was cooled to 2 – 4°C, stirred for 2 hours, filtered and washed with ethanol (50 mL). The wet product was dried under normal drying to get title compound 1 (Yield 60 g).

Example-5: Preparation of ethyl-2-(4,5-dihydrofuran-3-yl)-2-oxoacetate (VI).

2, 3-Dihydrofuran (250 g) was taken in toluene (2000 mL) and triethyl amine (505 g) was added to above solution. Ethyl oxalyl chloride (536.5 g) was slowly added to the above mixture by maintaining temperature at 25-30°C and maintained the stirring for 5 hours. After completion of reaction separated the organic layer, washed the organic layer with 8% sodium bicarbonate solution (2x500mL). Organic layer was distilled completely under vacuum to get title compound VI (Yield 560g).

1 H NMR : 1.38 (t, 3H), 2.93 (t, 2H), 4.34 (q, 2H), 4.63 (t, 2H), 8.02 (s, 1 H).

Example-6: Preparation of ethyl-2-(3-bromo-2-ethoxytetrahydrofuran-3-yl)-2-oxoacetate (V).

Ethyl-2-(4,5-dihydrofuran-3-yl)-2-oxoacetate (Vl, 100g) was dissolved in dichloromethane (500ml) and Ethanol (150mL) was added. The reaction mass was cooled to 5 to 10°C. N- bromosuccinimide (1 15 g) was added lot wise by maintaining temp below 10°C. Reaction mass was then stirred at 20-30°C till completion of reaction. Reaction mass was washed with sodium bicarbonate solution (2%, 3x400mL) and the organic layer was used for the next step.

Example-7: Preparation of hexahydrofuro [2, 3-b] furan-3-ol (IV).

To the solution of Ethyl-2-(3-bromo-2-ethoxy tetra hydrofuran-3-yl)-2-oxoacetate in dichloromethane (V, 500mL) as prepared in above example, sodium sulphite solution (225g was dissolved in 1700mL of water) was added at 25-35°C. Reaction mass was stirred for 5-8hours at the same temperature and separated the organic and aqueous layers. Organic layer was washed with water (340mL). Distilled out the solvent completely get ethyl-2-(2-ethoxy tetra hydrofuran-3- yl)-2-oxoacetate. Sodium borohydride (35.5g)was dissolved in ethanol (400mL) under nitrogen atmosphere, ethyl-2-(2-ethoxytetra hydrofuran-3-yl)-2-oxoacetate was dissolved in ethanol (100mL) and slowly added to above solution at 15-30°C. Reaction mass was heated to 30-45X, maintained for 5-8 hours, the reaction mass temperature was raised to 55°C and stirred for 8 hours. The reaction mass was cooled to 20-30°C, ammonium chloride solution (1 5g in 200mL water) was slowly added and stirred for 1-2hours. The reaction mass was filtered and filtrate was distilled out under vacuum to get residue. Dichloromethane (600mL) was added to residue and cooled to -10°C. Hydrochloric acid (85mL) was added slowly drop wise in 2 hours by maintaining temp -5 to 0°C, reaction mass was stirred for 60minutes at -5 to 0°C and distilled the solvent completely. The obtained residue was stripped out with isopropyl alcohol (2x200mL, 1x100mL), ethyl acetate (500mL) was added to the resultant residue, stirred for 30-60minutes and cooled to 10-15°C. The solution was filtered and filtrate was concentrated to get title compound IV (yield 56 g).

Example-8: Preparation of Hexahydrofuro [2, 3-b] furan-3-yl acetate (III).

Hexahydrofuro [2, 3-b] furan-3-ol (IV, 60g) was dissolved in dichloromethane (300mL) and cooled to 0-5°C. To the cooled solution triethylamine (58.2 g), N, N-dimethylaminopyridine (1.12g) was added, acetic anhydride (56.5g) was added for 30-60 minutes at the same temperature, the mass temperature was raised to 25-35°C and stirred for 2-4hours. After completion of reaction the mass was cooled to 10-20°C, water (120mL) was added, stirred for 30minutes, separated the organic layer, washed with 10% sodium chloride solution (120mL) and distilled out dichloromethane to get title compound (yield 72g). Further, the product was purified by fractional distillation to get pure Hexahydrofuro [2, 3-b] furan-3-yl acetate III (yield 54g).

1 H NMR : 1.9-2.09(m, 2H), 2.10(s, 3H), 3.0-3.1 (m, 1 H), 3.86-4.03(m, 2H), 3.73(dd, 1 H), 4.10(dd, 1 H), 5.19(m, 1 H), 5.72 (d, 1 H)

Example-9: Preparation of (3R, 3aS, 6aR)-Hexahydrofuro [2, 3-b] furan-3-yl acetate (II). To the buffer solution (104.3g of sodium dihydrogen orthophosphate dissolved in 530mL of water & pH adjusted to 6.0-6.5 with saturated sodium bicarbonate solution(68g in 680 mL water) solution) hexahydrofuro [2, 3-b] furan-3-yl acetate (111,115g) and CAL-B (17.25g) was added at 25-35°C, heated to 38-45°C and stirred for 24 hours. CAL-B (17.25g) was added stirred for 16 hours, again CAL- B (11.5g) was added at 38-45°C and stirred for 16 hours (pH should maintain 6.0-6.5). The reaction mass was cooled to 20-30°C, methylenedichloride (1 150mL) was added to the mass and stirred for 30 minutes. The reaction mass was filtered through hyflowbed then separated the organic layer and washed with 10%sodiumchloride solution (575mL). Organic layer was distilled completely under vacuum to get title compound II (yield 40. Og). Example-10: Preparation of (3R, 3aS, 6aR)-Hexahydrofuro [2, 3-b] furan-3-ol (I).

(3R, 3aS, 6aR)-Hexahydrofuro [2, 3-b] furan-3-yl acetate (II, 14.0g) was dissolved in methanol (42mL). Potassium carbonate (0.34g) was added and stirred at 25-35°C for 6-8hours. Methanol was distilled out completely under vacuum, to the distillate methylenedichloride (28mL) was added, stirred the mass for 30 minutes and again distilled the solvent to get residue. Dissolved the residue in dichloromethane (56mL), the resultant solution was treated with carbon and the solvent was completely distilled out get title compound I (yield 10.5g). Example-11 : Preparation of (3R, 3aS, 6aR)-Hexahydrofuro [2, 3-b]-furan-3-yl-4-nitrophenyl carbonate (2).

To the solution of (3R, 3aS, 6aR)-Hexahydrofuro [2, 3-b] furan-3-ol (l,100g) and Bis-nitrophenyl carbonate (257.2g) in methylene dichloride (1200mL), triethylamine solution (132 g in 300 mL of methylene dichloride) was added slowly at 20-30°C for 2-3hours. Maintained the reaction at the same temperature for 8-10hours, after completion of reaction water (500mL) was added for 30- 60minut.es and settled the reaction mass then separated the organic layer. Organic layer was washed with 10% acetic acid (100mL) and 10% sodium chloride solution (500mL), distilled the organic layer and co distilled with ethyl acetate (100mL). Ethyl acetate (300mL) was added to the distillate and heated to 50-55°C for 30-45minut.es to get clear solution, the solution was cooled to 5-10°C and maintained at the same temperature for 60 minutes. The obtained solid was filtered, washed with ethanol (100mL) and dried the wet material at 40-45°C for 10-14 hours to get title compound 2 (yield 160g). Example-12: Preparation of dimethylformamide solvate of Darunavir.

To a mixture of 4-amino-N-(2r,3S)(3-amino-2-hydroxy-4-phenylbutyl)-N-lsobutyl- benzenesulfonamide (1 ,25g) and N-methyl-2-pyrrolidinone (NMPO, 50mL), a solution of (3R,3aS,6aR)-Hexahydrofuro[2,3-b]-furan-3-yl-4-nitrophenyl carbonate (2, 8.85g) and N-methyl- 2-pyrrolidinone (75mL) was added at -5 to 0°C for 2 to 3 hours under nitrogen atmosphere. The mass temperature was slowly raised to 25 to 30°C and stirred for 6 to 8 hours. The reaction mass was quenched in to the solution of methylene chloride (125mL) and water (250mL) at 25-35°C for 30 to 45 minutes. Separated the organic layer followed by washed with 10% sodium carbonate solution (150mL), 10% sodium chloride solution (150mL) and with water (6x150mL). Organic layer was dried over sodium sulphate and distill off the solvent under vacuum at below 50°C to obtain darunavir as a residue. To the residue Ν,Ν-dimethyl formamide (50mL) was added and cooled to 0 to -5°C, water (25mL) was added to the solution and maintained for 12hours at 0 to -5 °C, the obtained solid was filtered and washed with pre-cooled mixture of N,N-dimethyl formamide & water (25mL+25mL) to get dimethylformamide solvate of darunavir.

Example-13: Preparation of non-solvated crystalline Darunavir.

To a mixture of 4-amino-N-(2r,3S)(3-amino-2-hydroxy-4-phenylbutyl)-N-lsobutyl- benzenesulfonamide (1, 25g) and N-methyl-2-pyrrolidinone (NMPO, 50mL), a solution of (3R,3aS,6aR)-Hexahydrofuro[2,3-b]-furan-3-yl-4-nitrophenyl carbonate (2, 18.85g) and N- methyl-2-pyrrolidinone (75mL) was added at -5 – 0°C for 2 to 3 hours under nitrogen atmosphere. The mass temperature was slowly raised to 25 – 30°C and stirred for 6 to 8 hours. The reaction mass was quenched in to the solution of methylene chloride (250mL) and water (250mL) at 25- 35°C for 30 – 45 minutes. Separated the organic layer followed by washed with 10% potassium carbonate solution (5x125mL), water (5x125mL), 20% sodium chloride solution (25mL), finally washed with 20% citric acid solution (125mL). The organic layer was treated with carbon and distilled off the solvent under vacuum at below 50°C to obtain darunavir as a residue. To the residue ethylacetate (250mL) was added and cooled to 0 to -5°C, to the cooled solution hexane (225mL) was added and maintained for 12hours at 0 to -5 °C, the obtained solid was filtered, washed with pre-cooled mixture of ethylacetate and hexane (25mL+25mL) and dried the compound to get non-solvated crystalline darunavir(yield 25g).

Example -14: Preparation of Amorphous Darunavir.

Darunavir (200g) as obtained in above example was dissolved in methylene dichloride (10L) and washed with water (3×1000 mL). Organic layer was taken into agitated thin film dryer (ATFD) feed tank. Applied initial temperature about 36 – 40°C and high vacuum (580mm/Hg) to the vessel. Slowly feed the solution to the Vessel (feed rate 5L r) over 1hour finally given the methylene chloride (3L) flushing. The material is collected in the material collecter. Dried at 58 -62°C for 40 hours to get amorphous darunavir (yield 160g).

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http://www.google.com/patents/WO2011048604A2?cl=en

Preparation of Durumvir ethanolate

A solution of (3R,3aS,6a ?)-hexahydrofuro[2,3-D]furan-3-yl 4-nitrophenyl carbonate (5b, 75.4 g) in A -methyl-2-pyrrolidinone (300 mL) was added to a pre-cooled (-2 ± 2°C) solution of the compound of formula 4 (100 g) in W-methyl-2-pyrrolidinone (200 mL) at -4 to 0°C over a period of 2 h. The temperature of the reaction mass was slowly raised to 25 – 30°C and maintained for 8 h. After completion of the reaction (TLC monitoring), ethyl acetate (1000 mL) and purified water (500 mL) were added to the reaction mass. The layers were separated; organic layer was washed with sodium carbonate solution (2 X 500 mL) followed by sodium chloride solution. The organic layer was concentrated; ethanol (300 mL) was added, heated to 45 – 50°C, maintained for 1 h, filtered and washed with ethanol. The wet compound was taken into a mixture of ethyl acetate- ethanol (7:93, 600 mL), heated to reflux, charcoal was added and filtered. The resultant filtrate was cooled to 0 – 5°C, filtered the separated solid and washed with ethanol. The wet compound was dried at 45°C to obtain the in 124.3 g (yield-82.5%). The obtained Darunavir ethanolate had purity of 99.79% on area by HPLC and contained 0.08% on area by HPLC of the difuranyl impurity. Preparation of Amorphous Darunavir

Example – 4

A solution of Darunavir ethanolate (200 g) in dichloromethane (10 L) was taken into ATFD Feed tank. The solvent was evaporated by fed the solution slowly to the ATFD Vessel (feed rate 5 L /h) at 36 – 40°C and high vacuum (580 mm/Hg) over 2 h and then flushed with dichloromethane (3 L). The material is collected in the material collector in 160g with the HPLC Purity of 99.60% and particle size D₅₀ of approximately 50 micrometers and D_go of approximately 100 to 180 micrometers. Example-5

Darunavir Ethanolate (200 gm) was dissolved in Methylene chloride (1000 ml) and solvent was evaporated by applying vacuum followed by isolation of amorphous Darunavir as a solid as such or by charging n-Heptane or Isopropyl ether. Example – 6

Darunavir Ethanolate (10 g) was dissolved in ethyl acetate (50 mL). The solution was heated to 40 – 45°C and maintained for 30 min. Ethyl acetate was distilled off under vacuum completely to get residue in the form of semisolid. n-Heptane (50 mL) was added to the residue and stirred for 30 min. at ambient temperature. The separated solid was filtered, washed the wet cake with n-heptane (5 mL) and dried at 40 – 45°C under vacuum to get 8.0 g of amorphous Darunavir.

Example – 7

Darunavir Ethanolate (10 g) was placed into a dry round bottom flask and heated to 110 – 120°C to melt and maintained under vacuum for 4 h. The reaction mass was slowly cooled to 25 – 35°C. The obtained glass type crystal was broken into powder to afford 8.5 g of amorphous Darunavir.

Example – 8

Darunavir Ethanolate (5.0 g) was suspended into glycerol (25 g), heated to 110 – 120°C under vacuum and maintained for 30min. Water (50 mL) was added to the cooled reaction mass at 25 – 35°C under stirring and the obtained suspension was stirred for 30 min at 25 – 35°C. The separated solid was filtered and dried at 40 – 45°C under vacuum to yield 3.5 g of amorphous Darunavir. Example – 9

Carbonic acid [(1 R,2S)-1-{((4-amino-benzenesulfonyl)-isobutyl-amino)-methyl}-2- ((3/?,3aS,6aR)-hexahydro-furo[2,3-ft]furan-3-yloxycarbonylamino)-3-phenyl-propylester (3R,3aS,6a ?)-hexahydro-furo[2,3- )]furan-3-yl ester (difuranyl impurity, 1).

The difuranyl impurity (1) isolated from the mother liquor by preparative HPLC using a mixture of formic acid-water (1 :99) as eluent. The ¹H-NMR, ¹³C-NMR and mass spectral data complies with proposed structure.

¹H-NMR (DMSO-cfe, 300 MHz, ppm) – δ 0.79 (d, J=6.6 Hz, 6H, 15 & 15′), 1.14-1.20 (m, 1 H, 20Ha), 1.34-1.42 (m, 1 H, 20Hb), 1.75-1.85 (m, 2H, 20′Ha & 14), 1.94-2.01(m, 1 H, 20′Hb), 2.54-2.64 (m, 2H, 8Ha & 13Ha), 2.74-2.89 (m, 3H, 8Hb, 13Hb & 19), 3.00-3.11 (m, 2H, 5Ha & 19′), 3.34-3.39 (m, 1H, 5Hb), 3.54-2.63 (m, 3H, 21 Ha & 17Ha), 3.65-3.74 (m, 3H, 21′Ha, 21 Hb &17Hb), 3.81-3.89 (m, 2H, 21′Hb & 17′Ha), 3.94-4.04 (m, 2H, 7 & 17′Hb), 4.81-4.88 (m, 1 H, 6), 4.92-4.96 (m, 1 H, 18′), 5.03-5.10 (m, 1 H, 18), 5.11 (d, J=5.4 Hz, 1 H, 22′), 5.61 (d, J=5.1 Hz, 1 H, 22), 6.03 (brs, 2H, NH₂, D₂0 exchangeable), 6.63 (d, J=8.7 Hz, 2H, 2 & 2″), 7.15-7.28 (m, 5H, 10H, 10Ή, 11 H, 11′ & 12), 7.40 (d, J=8.7 Hz, 2H, 3 & 3′), 7.55 (d, J=9.3 Hz, 1 H, NH, D₂0 exchangeable).

“H-NMR (DMSO-d₆, 75 MHz, ppm)- δ 19.56 & 19.81 (15C & 15′C), 25.42 (20 ), 25.47 (20C), 26.28 (14C), 35.14 (8C), 44.45(19′C), 45.01 (19C), 49.21 (5C), 53.39 (7C), 57.55 (13C), 68.70 (21 ‘C), 68.74 (21C), 69.95 (17′C), 70.20(17C), 72.65 (6C), 76.27 (18C), 79.59 (18′C), 108.70 (22′C), 108.75 (22C), 112.69 (2C), 122.56 (4C), 126.12 (12C), 128.04 (11 C & 11′C), 129.03 (10C & 10′C), 129.08 (3C), 138.03 (9C), 152.99 (1C), 153.55 (16′C), 155.32 (16C).

DIP MS: m/z (%) 1108 [M+Hf, 1131 [M+Naf

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http://www.google.com/patents/US20130244297

According to the present invention Darunavir having the below impurity not more than 0.1, preferably 0.05%.

………….

DARUNAVIR

Laninamivir

(4S,5R,6R)-5-acetamido-4-carbamimidamido-6-[(1R,2R)-3-hydroxy-2-methoxypropyl]-5,6-dihydro-4H-pyran-2-carboxylic acid

cas 203120-17-6,

Laninamivir (L174000) prodrug; a novel long-acting neuraminidase inhibitor.

laninamivir octanoate

472.53254, C21H36N4O8,   cas no 203120-46-1, R-125489, CS-8958 

Daiichi Sankyo (Originator)

R-118958 is a potent, long-acting neuraminidase inhibitor (LANI) approved and launched in 2010 in Japan as an inhalable formulation for the treatment of influenza A and influenza B in adults and pediatric patients. In 2013 the product was approved in Japan for the prevention of influenza A and influenza B.

ATLANTA, Dec. 20, 2013 (GLOBE NEWSWIRE) — Biota Pharmaceuticals, Inc.
(Nasdaq:BOTA) (“Biota” or the “Company”) today reported that Daiichi Sankyo Company, Limited (“Daiichi Sankyo”) has been granted regulatory approval in Japan to manufacture and market Inavir(R) Dry Powder Inhaler 20mg (generic name laninamivir octanoate) for the prevention of influenza A and B. Inavir(R) was successfully developed and launched by Daiichi Sankyo in Japan for treatment of influenza A and B viruses in October, 2010. Biota is developing laninamivir octanoate outside of Japan for the treatment of influenza, and is currently conducting a large, multi-national Phase 2 trial of laninamivir octanoate in adults infected with influenza. In 2003, the Company and Daiichi Sankyo entered into a collaboration and license agreement to develop long-acting neuraminidase inhibitors, including laninamivir octanoate, and in March 2009, the parties entered into a commercialization agreement, pursuant to which Daiichi Sankyo obtained exclusive marketing rights to laninamivir octanoate in Japan.http://www.pharmalive.com/biota-flu-drug-okd-in-japan

Laninamivir (CS-8958) is a neuraminidase inhibitor which is being researched for the treatment and prophylaxis of Influenzavirus A and Influenzavirus B.^[1] It is currently in Phase III clinical trials. ^[2]

Laninamivir was approved for influenza treatment in Japan in 2010 and is currently marketed under the name “Inavir” by Daiichi Sankyo. Biota Pharmaceuticals ^[3] and Daiichi Sankyo co-own Laninamivir. On 1st April 2011, BARDA awarded up to an estimated U$231m to Biota Pharmaceuticals (Formerly Biota Holdings Ltd) wholly owned subsidiary, Biota Scientific Management Pty Ltd, for the advanced development of Laninamivir in the US. ^[4]

patent

The recent flu scares – first H5N1 bird flu and then H1N1 swine flu – transformed Roche’s neuraminidase inhibitor Tamiflu (oseltamivir) into a household name, along with GSK’s Relenza (zanamivir). Both of these require twice-daily dosing, and the orally available oseltamivir is the first choice, but resistance is starting to appear.

A new neuraminidase inhibitor, laninamivir, is being developed by Daiichi Sankyo.5 When administered as the octanoate prodrug form, it appears that a single dose might be sufficient to treat influenza, weekly doses could be preventative, and it is active against extremely pathogenic H5N1 strains.

Laninamivir octanoate

In a double blind, randomised, placebo-controlled Phase I study in 76 healthy male volunteers, subjects were given inhaled single doses of 5, 10, 20, 40, 80 or 120mg of the prodrug, or twice-daily doses of 20 or 40mg for three days.6 No adverse events were observed, and while the prodrug disappeared from the plasma with a half-life of about two hours, the laninamivir itself was much more slowly eliminated, with a half-life of the order of three days, suggesting the potential for giving long-lasting activity against influenza.

In another Phase I trial, a total of 20 healthy subjects with renal function ranging from normal to severely impaired were given single inhaled 20mg doses of the prodrug.7 The degree of renal impairment did not affect the maximum concentration or the time to achieve it, but the half-life increased as renal function reduced. This indicates that the rate-limiting step for elimination is drug release rate to plasma from tissues rather than renal excretion. It was well tolerated, but systemic exposure increased with increasing renal impairment.

It has also been compared with oseltamivir in patients with influenza. A total of 186 children under 10 who had had febrile influenza symptoms for no longer than 36 hours were randomised to receive 20 or 40mg of laninamivir octanoate as a single inhalation or 2mg/kg oseltamivir orally twice a day for five days.8

The new drug gave a significant reduction, of 61 hours for the 40mg group and 66 for the 20mg group, in median time to illness alleviation compared with oseltamivir in those with oseltamivir-resistant H1N1 influenza A. However, there was no significant difference in the time to alleviation of illness with H3N2 influenza A, or influenza B.

The most common side-effects were gastrointestinal problems.

In a Phase III trial, a total of 1,003 adult patients with febrile influenza symptoms for no more than 36 hours were given similar doses to those in the trial in children.9 Median time to alleviation of illness was 73h for 40mg, 86h for 20mg, and 74h for oseltamivir, and the proportion of patients shedding virus at day 3 was significantly lower in the 40mg group than for those given oseltamivir.

1.  Yamashita M, Tomozawa T, Kakuta M, Tokumitsu A, Nasu H, Kubo S (January 2009).“CS-8958, a prodrug of the new neuraminidase inhibitor R-125489, shows long-acting anti-influenza virus activity”. Antimicrobial Agents and Chemotherapy 53 (1): 186–92.doi:10.1128/AAC.00333-08. PMC 2612152. PMID 18955520.
2.  Hayden F (January 2009). “Developing new antiviral agents for influenza treatment: what does the future hold?”. Clinical Infectious Diseases. 48. Suppl 1 (S1): S3–13.doi:10.1086/591851. PMID 19067613.
3.  http://www.biotapharma.com
4. http://www.biotapharma.com/?page=1021001&subpage=1021019

5. T. Honda et al. Synthesis and in vivo influenza virus-inhibitory effect of ester prodrug of 4-guanidino-7-O-methyl-Neu5Ac2en, Bioorg Med Chem Lett 2009, 19(11): 2938

6. H. Ishizuka et al. J. Clin. Pharmacol. 2010, 50, 1319

7. H. Ishizuka et al. J. Clin. Pharmacol. 2010, epub ahead of print, doi 10.1177/0091270010361914

8. N. Sugaya and Y. Ohashi, Antimicrob. Ag. Chemother. 2010, 54, 2575

9 A. Watanabe et al. Clin. Inf. Dis. 2010, 51, 1167

A new route toward 2-acetamido-4-O-methyl-2-deoxy-D-mannopyranose from a Ferrier derivative of tri-O-acetyl-D-glucal, which contributes to aldolase-catalyzed synthesis of laninamivir (CS-8958)
Tetrahedron 2013, 39(37): 7931

Infection of poultry with H5N1 avian influenza virus has been expanding since 2003 in wide areas including Asia, Europe and Africa. Humans infected with this virus have been found not only in Asia but also in Middle East and Africa. If a new type of H5N1 influenza virus has appeared and its infection has started, it is believed that the infection will rapidly expand to cause a worldwide spread (i.e., influenza pandemic) because most people do not possess immunity against that virus and influenza viruses spread via droplet infection and airborne infection. More than half of human patients infected with H5N1 influenza virus have died so far. Thus, the virus is highly pathogenic. It is known that three influenza pandemics, the Spanish Flu, the Asian Flu and the Hong Kong Flu, occurred in the 20th century. In the Spanish Flu which caused the largest number of patients, it is estimated that about 20-40 million people died in the world and about 0.5 million people in Japan.

According to a report from Japanese Ministry of Health, Labour and Welfare made in November, 2005, if a new type influenza virus has spread, the number of patients who will consult medical doctors in Japan as a result of infection with that virus is estimated about 18-25 million. Further, when the pathogenicity of that new type influenza virus is severe, the number of inpatients is estimated about 0.2 million while the number of dead is estimated about 0.64 million. Therefore, not only health hazard but also significant influences upon social activities are feared.

Thus, a new type influenza can cause a highly severe disease. Early development of effective therapeutics is demanded.

Although it is reported that zanamivir (in particular, zanamivir hydrate) and oseltamivir (in particular, oseltamivir phosphate or oseltamivir carboxylate) which are influenza therapeutics with neuraminidase inhibitory activity show an inhibitory activity against H5N1 influenza virus, compounds with more excellent activity are desired (Non-Patent Document 1 or 2). Further, H5N1 influenza virus strains against which oseltamivir does not show any inhibitory activity (i.e., oseltamivir resistant virus strains) have been reported. Compounds which possess an inhibitory activity against these oseltamivir resistant H5N1 influenza virus strains are desired (Non-Patent Document 1 or 2).

Compounds represented by formula (I) are known to be useful as influenza therapeutics with neuraminidase inhibitory activity (Patent Documents 1 to 3). However, it has not been reported that these compounds have an inhibitory activity against H5N1 influenza virus. Further, the structures of the compounds represented by formula (I) resemble the structure of zanamivir but are completely different from the structure of oseltamivir.

Non-Patent Document 1: Nature, 2005, vol. 437, p. 1108

Non-Patent Document 2: N. Engl. J. Med., 2005, vol. 353, (25):2667-72
Patent Document 1: U.S. Pat. No. 6,340,702 (Japanese Patent No. 3209946)
Patent Document 2: U.S. Pat. No. 6,451,766 (Japanese Patent Publication No. Hei 10-109981)
Patent Document 3: U.S. Pat. No. 6,844,363 (Japanese Patent Publication No. 2002-012590)

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US20100204314

Preparation Example 1 5-Acetamido-4-guanidino-9-O-octanoyl-2,3,4,5-tetradeoxy-7-O-methyl-D-glycero-D-galacto-non-2-enopyranosoic acid

(1) Diphenylmethyl 5-acetamido-4-(N,N-bis-t-butyloxycarbonyl)guanidino-9-O-octanoyl-2,3,4,5-tetradeoxy-7-O-methyl-D-glycero-D-galacto-non-2-enopyranosoate (3.46 g, 4.1 mmol) disclosed in Example 35 (i) of U.S. Pat. No. 6,340,702 (Japanese Patent No. 3209946) was dissolved in methylene chloride (27 ml) and trifluoroacetic acid (14 ml). The resultant solution was stirred at room temperature overnight. The reaction solution was concentrated to dryness under reduced pressure, followed by three cycles of azeotropic distillation to dryness with toluene (5 ml). The resultant oily material was dissolved in ethyl acetate (10 ml). The solution was poured into a saturated aqueous solution of sodium hydrogencarbonate (50 ml). The pH of the resultant solution was adjusted to 8.5 by addition of 20% aqueous solution of sodium carbonate. Then, the solution was stirred at room temperature for 3 hr and its pH was adjusted to 5.0 with hydrochloric acid (3 ml), followed by stirring at room temperature for another 1 hr. The solution was further stirred for 1 hr while ice-cooling. Subsequently, precipitating crystals were suction filtered and vacuum dried for 10 hr at an external temperature of 50° C. The resultant crystals were left in the air for one day to thereby yield the subject compound as a hydrate crystal (0.97 g; yield 51%).

Infrared Absorption Spectrum (KBr) ν max cm⁻¹: 3412, 2929, 2856, 1676, 1401, 1320, 1285, 1205, 1137, 722.

¹H Nuclear Magnetic Resonance Spectrum (400 MHz, CD₃OD) δ ppm: 5.88 (1H, d, J=2.5 Hz), 4.45 (3H, m), 4.27 (1H, dd, J=10.0 Hz, 10.0 Hz), 4.15 (1H, m), 3.47 (21-1, m), 3.42 (3H, s), 2.37 (2H, t, J=7.4 Hz), 2.10 (3H, s), 1.31 (2H, m), 1.20-1.40 (8H, m), 0.85-0.95 (3H, m).

¹³C Nuclear Magnetic Resonance Spectrum (100 MHz, CD₃OD) δ ppm: 176.5, 173.7, 164.7, 158.9, 146.7, 108.7, 80.1, 78.0, 69.3, 66.8, 61.4, 52.4, 35.1, 32.8, 30.2, 30.1, 26.0, 23.7, 22.8, 14.4.

(2) The subject compound was also obtained by the method described below.

5-Acetamido-4-guanidino-9-O-octanoyl-2,3,4,5-tetradeoxy-7-O-methyl-D-glycero-D-galacto-non-2-enopyranosoic acid trifluoroacetic acid salt (3.0 g, 5.1 mmol) disclosed in Example 35 (ii) of U.S. Pat. No. 6,340,702 (Japanese Patent No. 3209946) was subjected to reversed phase column chromatography [Cosmosil 75C 18PREP (nacalai tesque), 100 g] and eluted with methanol/water (0/1-1/1-2/1). Fractions containing the compound of interest were vacuum concentrated. The precipitating crystals were suction filtered and vacuum dried. The resultant crystals were left in the air for one day to thereby yield the subject compound as a hydrate crystal (1.2 g; yield 49%). The property data of the resultant compound were consistent with those of the compound obtained in (1) above.

Preparation Example 2 5-Acetamido-4-guanidino-2,3,4,5-tetradeoxy-7-O-methyl-D-glycero-D-galacto-non-2-enopyranosoic acid

5-Acetamido-4-guanidino-2,3,4,5-tetradeoxy-7-O-methyl-D-glycero-D-galacto-non-2-enopyranosoic acid trifluoroacetic acid salt (3.0 g, 5.1 mmol) disclosed in Example 28 (viii) of U.S. Pat. No. 6,340,702 (Japanese Patent No. 3209946) was purified in an ion-exchange resin column [Dowex-50X; (i) water and (ii) 5% aqueous ammonium solution] and further purified by reversed phase column chromatography [Cosmosil 75C 18PREP (nacalai tesque); water]. Fractions containing the compound of interest were vacuum concentrated. The resultant solid was washed with methanol, filtered and dried to thereby yield the subject compound (1.43 g) as a colorless solid.

¹H Nuclear Magnetic Resonance Spectrum (400 MHz, CD₃OD) δ ppm: 5.64 (1H, d, J=2.0 Hz), 4.43 (2H, m), 4.22 (1H, dd, J=10.0 Hz, 10.0 Hz), 4.00 (1H, m), 3.85 (1H, dd, J=10.0 Hz, 2.4 Hz), 3.68 (1H, dd, J=10.0 Hz, 5.5 Hz), 3.58 (1H, m), 3.43 (3H, s).

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WO 2013089168

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US8455659

Process W is known as a method for manufacturing a compound represented by the formula (Ia), which is embraced in a compound represented by the formula (I) or a pharmacologically acceptable salt thereof, (hereinafter also referred to as “compound (Ia)”; the same shall be applied with respect to other (Patent Document 1). In Process W, n-Hep represents a 1-heptyl group.

Process X is known as a method for manufacturing compound (Ib), which is embraced in compound (I) or a pharmacologically acceptable salt thereof (Patent Document 2). Compound (IVk) is a synthetic intermediate in Process W. In Process X, n-Hep represents a 1-heptyl group.

Process Y is known as a method for manufacturing compound (IIIa), which is a trifluoroacetic acid salt of compound (III) (Non-patent Document 1). The procedures from compound (IVc) to compound (IVe) and from compound (IVf) to compound (IVh) in Process Y are the same as in Process W.

Process Z is known as a method for manufacturing compound (IIIa), which is a trifluoroacetic acid salt of compound (III) (Non-patent Document 2). In Process Z, the procedure from compound (IVf) to compound (IVh) is the same as in Process W, and the procedure from compound (IVh) to compound (IIIa) is the same as in Process Y.

From the viewpoint of industrial production, the aforementioned Process W, Process Y, or Process Z could be improved in points such as the following:

GRAZOPREVIR

• Grazoprevir hydrate
• UNII-4O2AB118LA
• MK 5172

THERAPEUTIC CLAIM Antiviral

CHEMICAL NAMES

1. Cyclopropanecarboxamide, N-[[[(1R,2R)-2-[5-(3-hydroxy-6-methoxy-2-
quinoxalinyl)pentyl]cyclopropyl]oxy]carbonyl]-3-methyl-L-valyl-(4R)-4-hydroxy-L-prolyl-1-
amino-N-(cyclopropylsulfonyl)-2-ethenyl-, cyclic (1→2)-ether, hydrate (1 :1) (1R,2S)-

2. (1aR,5S,8S,10R,22aR)-N-{(1R,2S)-1-[(cyclopropylsulfonyl)carbamoyl]-2-
ethenylcyclopropyl}-5-(1,1-dimethylethyl)-14-methoxy-3,6-dioxo-
1,1a,3,4,5,6,9,10,18,19,20,21,22,22a-tetradecahydro-8H-7,10-
methanocyclopropa[18,19][1,10,3,6]dioxadiazacyclononadecino[11,12-b]quinoxaline-8-
carboxamide hydrate

MOLECULAR FORMULA C38H50N6O9S.H2O
MOLECULAR WEIGHT 784.92

SPONSOR Merck Sharp & Dohme Corp.

CAS REGISTRY NUMBER 1350462-55-3  HYDRATE, 1350514-68-9 (anhydrous)

WHO NUMBER
9857

GRAZOPREVIR

MERCK

MK-5172 is in phase II clinical development at Merck & Co. for the oral treatment of chronic hepatitis C in combination with peginterferon and ribavirin and in combination with MK-8742. Phase I clinical trials are ongoing for the treatment of hepatitis C in patients with genotype 1 and genotype 3. In 2013, breakthrough therapy designation was assigned to the compound.

Discovery of MK-5172, a macrocyclic hepatitis C virus NS3/4a protease inhibitor
ACS Med Chem Lett 2012, 3(4): 332DOI: 10.1021/ml300017p

Development of a practical, asymmetric synthesis of the hepatitis c virus protease inhibitor MK-5172
Org Lett 2013, 15(16): 4174

References on MK-5172 hydrate:
[1]. Steven Harper , John A. McCauley , Michael T. Discovery of MK-5172, a Macrocyclic Hepatitis C Virus NS3/4a Protease Inhibitor. ACS Med. Chem. Lett., 2012, 3 (4), pp 332-336[2]. Summa V, Ludmerer SW, McCauley JA, MK-5172, a selective inhibitor of hepatitis C virus NS3/4a protease with broad activity across genotypes and resistant variants. Antimicrob Agents Chemother. 2012 Aug;56(8):4161-7.

WO2013142159

WO 2013106631

WO 2013101550

WO 2013028470

WO 2013028471

WO2013028465

WO 2010011566

Description:
IC50 Value: 7.4nM and 7nM for genotype1b and 1a respectively, in replicon system [1]
MK-5172 is a novel P2-P4 quinoxaline macrocyclic HCV NS3/4a protease inhibitor currently in clinical development.
in vitro: In biochemical assays, MK-5172 was effective against a panel of major genotypes and variants engineered with common resistant mutations observed in clinical studies with other NS3/4a protease inhibitors. In the replicon assay, MK-5172 demonstrated subnanomolar to low-nanomolar EC50s against genotypes 1a, 1b, and 2a [2].
in vivo: In rats, MK-5172 showed a plasma clearance of 28 ml/min/kg and plasma half-life of 1.4 hr. When dosed p.o. at 5 mg/kg, the plasma exposure of MK-5172 was good with an AUC of 0.7 uM.hr. The liver exposure of the compound was quite good (23 uM at 4 hr), and MK-5172 remained in liver 24 hr after a single p.o. 5 mg/kg dose. At 24 hr, the liver concentration of MK-5172 was 0.2 uM, which was over 25-fold higher than the IC50 in the replicon assay with 50% NHS. When dosed to dogs, MK-5172 showed low clearance of 5 ml/min/kg and a 3 hr half-life after i.v. 2 mg/kg dosing and had good plasma exposure (AUC=0.4 uM.hr) after a p.o. 1 mg/kg dose [1].
Clinical trial: Evaluation of Hepatic Pharmacokinetics for MK-5172 in Participants With Chronic Hepatitis C . Phase1

Hepatitis C virus (HCV) infection is a major health problem that leads to chronic liver disease, such as cirrhosis and hepatocellular carcinoma, in a substantial number of infected individuals. Current treatments for HCV infection include immunotherapy with recombinant interferon-α alone or in combination with the nucleoside analog ribavirin.

Several virally-encoded enzymes are putative targets for therapeutic intervention, including a metalloprotease (NS2-3), a serine protease (NS3), a helicase (NS3), and an RNA-dependent RNA polymerase (NS5B). The NS3 protease is located in the N-terminal domain of the NS3 protein. NS4A provide a cofactor for NS3 activity.

Potential treatments for HCV infection have been discussed in the different references including Balsano, Mini Rev. Med. Chem. 8(4):307-318, 2008, Rönn et al., Current Topics in Medicinal Chemistry 8:533-562, 2008, Sheldon et al., Expert Opin. Investig. Drugs 16(8):1171-1181, 2007, and De Francesco et al., Antiviral Research 58:1-16, 2003

Different HCV inhibitors are described in different publications. Macrocyclic compounds useful as inhibitors the HCV protease inhibitors are described in WO 06/119061, WO 7/015785, WO 7/016441, WO 07/148,135, WO 08/051,475, WO 08/051,477, WO 08/051,514, WO 08/057,209. Additional HCV NS3 protease inhibitors are disclosed in International Patent Application Publications WO 98/22496, WO 98/46630, WO 99/07733, WO 99/07734, WO 99/38888, WO 99/50230, WO 99/64442, WO 00/09543, WO 00/59929, WO 02/48116, WO 02/48172, British Patent No. GB 2 337 262, and U.S. Pat. No. 6,323,180.

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nmr

¹³C NMR (100 MHz, DMSO-d₆) δ 172.32, 170.63, 169.04, 159.86, 156.95, 154.74, 148.10, 140.41, 133.55 (2 signals), 128.94, 118.21, 117.58, 105.89, 74.88, 59.75, 58.71, 55.68, 54.13, 54.01, 40.13, 34.49, 34.04, 33.76, 32.68, 30.71, 30.43, 28.55, 27.69, 27.28, 26.38, 21.98, 18.49, 10.67, 5.69, 5.46; MS (ES⁺) m/z 767 (M+H)⁺

(1aR,5S,8S,10R,22aR)-5-tert-butyl-N-((1R,2S)-1-{[(cyclopropylsulfonyl)amino]carbonyl}-2-vinylcyclopropyl)-14-methoxy-3,6-dioxo-1,1a,3,4,5,6,9,10,18,19,20,21,22,22a-tetradecahydro-8H-7,10-methanocyclopropa[18,19][1,10,3,6]dioxadiazacyclononadecino[11,12-b]quinoxaline-8-carboxamide

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NMR OF GRAZOPREVIR K SALT

Potassium {[(1R,2S)-1-({[(1aR,5S,8S,10R,22aR)-5-tert-butyl-14-methoxy-3,6-dioxo-
1,1a,3,4,5,6,9,10,18,19,20,21,22,22a-tetradecahydro-8H-7,10-
methanocyclopropa[18,19][1,10,3,6]dioxadiazacyclononadecino[11,12-b]quinoxalin-8-
yl]carbonyl}amino)-2-ethenylcyclopropyl]carbonyl}(cyclopropylsulfonyl)azanide (15 K-salt).

1H NMR (400 MHz, DMSO-d6) δ 7.91 (br s, 1 H), 7.75 (d, J =
8.3 Hz, 1 H), 7.15 (m, 1 H), 7.04 (m, 1 H), 5.97 (m, 1 H), 5.73 (br s, 1 H), 4.96 (m, 1 H), 4.79 (apparent q, J = 9.3 Hz, 1 H), 4.26 (dd, J = 9.7, 7.7 Hz, 1 H), 4.20 (d, J = 11.3 Hz, 1 H), 4.14 (d, J = 8.8 Hz, 1 H), 3.90 (dd, J = 11.1, 3.2 Hz, 1 H), 3.86 (s, 3 H), 3.62 (m, 1 H), 2.86-2.60 (m, 3 H), 2.38 (m, 1 H), 2.21 (m, 1 H), 1.80-1.48 (m, 6 H), 1.42 (m, 5 H), 1.14 (m, 1 H), 0.95 (m, 10 H), 0.81 (m, 2 H), 0.72-0.50 (m, 3 H), 0.41 (m, 1 H) ppm.http://pubs.acs.org/doi/suppl/10.1021/ml300017p/suppl_file/ml300017p_si_001.pdf

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GRAZOPREVIR

(1aR,5S,8S,10R,22aR)-5-tert-Butyl-N-((1R,2S)-1-{[(cyclopropylsulfonyl)amino] carbonyl}-2-
vinylcyclopropyl)-14-methoxy-3,6-dioxo-1,1a,3,4,5,6,9,10,18,19,20,21,22,22a-tetradecahydro-8H-
7,10-methanocyclopropa[18,19][1,10,3,6]dioxadiazacyclononadecino[11,12-b]quinoxaline-8-
carboxamide (MK-5172, 15).

1H NMR (400 MHz, CD3
OD) δ 7.79 (dd, J = 9.6, 1.8 Hz, 1 H), 7.23 (s, 1 H), 7.22 (m, 1 H), 7.10 (d, J = 9.6 Hz, 1 H), 6.01 (apparent t, J = 3.6 Hz, 1 H), 5.74 (m, 1 H), 5.24 (dd, J = 17.0 Hz, 1.6 Hz, 1 H), 5.11 (dd, J = 10.4 Hz, 1.6 Hz, 1 H), 4.49 (d, J = 11.2 Hz, 1 H), 4.40 (m, 2 H), 4.13 (dd, J = 12.0 Hz, 4.0 Hz, 1 H), 3.92 (s, 3 H), 3.76 (m, 1 H), 2.92 (m, 2 H), 2.85 (m, 1 H), 2.55 (dd, J = 13.6 Hz, 6.4 Hz, 1 H), 2.28 (m, 1 H), 2.18 (apparent q, J =8.8 Hz, 1 H), 1.85 (dd, J = 8.0 Hz, 5.6 Hz, 1 H), 1.73 (m, 2 H), 1.5 (m, 2 H), 1.40 (dd, J = 9.6 Hz, 5.6 Hz, 1 H), 1.3 (m, 2 H), 1.23 (m, 4 H), 1.08 (s, 9 H), 0.99 (m, 2 H), 0.89 (m, 3 H), 0.73 (m, 1 H), 0.49 (m, 1 H) ppm; HRMS (ESI) m/z 767.3411 [(M+H)+; calcd for C38H51N6O9S: 767.3433].http://pubs.acs.org/doi/suppl/10.1021/ml300017p/suppl_file/ml300017p_si_001.pdf

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http://www.google.nl/patents/US8080654

SYNTHESIS OF INTERMEDIATES Intermediates A

Intermediate #	Structure	Name	Lit. Reference
A1		(1R,2S)-1-Amino-N- (cyclopropylsulfonyl)-2- vinylcyclopropanecarboxamide hydrochloride	Wang et al., U.S. Pat. No. 6,995,174

Intermediate B1 3-methyl-N-({[(1R,2R)-2-pent-4-en-1-ylcyclopropyl]oxy}carbonyl)-L-valine

Step 1: [(1E)-hepta-1,6-dien-1-yloxy](trimethyl)silane

A solution (0.5 M) of butenyl magnesium bromide in THF (1.4 eq) was treated at −78° C. with Cu(I) Br.SMe₂ (0.05 eq) and HMPA (2.4 eq). The mixture was stirred for 10 min, then a solution (1 M) of acrolein (1 eq) and TMSCl (2 eq) in THF was added over 1 h such that the internal temperature remained below −68° C. The resulting mixture was stirred at −78° C. for 2 h, then treated with excess Et₃N and diluted with hexane. After reaching room temperature, the mixture was treated with a small portion of H₂O and filtered through CELITE. The filtrate was washed 10 times with H₂O and then with brine. The organic layer was dried, and the volatiles were removed to give a residue that was distilled under reduced pressure (20 mbar). The fraction collected at 80-86° C. contained the title compound (58%) as a colorless liquid. ¹H NMR (400 MHz, CDCl₃) δ 6.19 (d, J=11.6 Hz, 1H), 5.85-5.75 (m, 1H), 5.02-4.92 (m, 3H), 2.08-2.02 (m, 2H), 1.94-1.88 (m, 2H), 1.46-1.38 (m, 2H), 0.18 (s, 9H).

Step 2: trans-2-pent-4-en-1-ylcyclopropanol

A solution (0.45 M) of the preceding compound in hexane was treated with a solution (15%) of Et₂Zn (1.2 eq) in toluene, and the resulting solution was cooled in an ice bath. Diiodomethane (1.2 eq) was added dropwise, then the solution was stirred for 1 h before being warmed to 20° C. Pyridine (6 eq) was added, and the slurry was stirred for 15 min then poured onto petroleum ether. The mixture was filtered repeatedly through CELITE until a transparent solution was obtained. This mixture was concentrated at 100 mbar, and the solution that remained (that contained trimethyl{[(trans)-2-pent-4-en-1-ylcyclopropyl]oxy}silane, toluene and pyridine) was further diluted with THF. The mixture was cooled to 0° C. then treated dropwise with a solution (1 M) of TBAF (1.2 eq) in THF. After 10 min, the mixture was allowed to warm to 20° C., and after a further 1 h was poured into H₂O. The aqueous phase was extracted with EtOAc, and the combined organic extracts were washed with brine then dried. Removal of the volatiles afforded a residue that was purified by flash chromatography (eluent 0-66% Et₂O/petroleum ether) to furnish the title compound (71%) as a colorless liquid. ¹H NMR (400 MHz, CDCl₃) δ 5.85-5.75 (m, 1H), 5.00 (dd, J=17.1, 1.6 Hz, 1H), 4.94 (br d, J=10.4 Hz, 1H), 3.20 (apparent dt, J=6.4, 2.5 Hz, 1H), 2.10-2.04 (m, 2H), 1.52-1.44 (m, 2H), 1.29-1.19 (m, 1H), 1.15-1.07 (m, 1H), 0.95-0.87 (m, 1H), 0.71-0.66 (m, 1H), 0.31 (apparent q, J=6.0 Hz, 1H).

Step 3: methyl 3-methyl-N-(oxomethylene)-L-valinate

A solution (0.39 M) of methyl 3-methyl-L-valinate in a 2:1 mixture of saturated aqueous NaHCO₃ and CH₂Cl₂ was cooled in an ice bath and stirred rapidly. The mixture was treated with triphosgene (0.45 eq) in one portion, and the resulting mixture was stirred for 0.5 h. The reaction was diluted with CH₂Cl₂, and the layers were separated. The aqueous phase was extracted with CH₂Cl₂, then the combined organics were washed with brine and dried. Removal of the solvent gave the title compound as clear oil that was kept for 12 h under vacuum (0.1 mbar) then used directly in the subsequent step. ¹H NMR (400 MHz, CDCl₃) δ 3.79 (s, 3H), 3.75 (s, 1H), 1.00 (s, 9H).

Step 4: methyl 3-methyl-N-({[(1R,2R)-2-pent-4-en-1-ylcyclopropyl]oxy}carbonyl)-L-valinate and methyl 3-methyl-N-({[(1S,2S)-2-pent-4-en-1-ylcyclopropyl]oxy}carbonyl)-L-valinate

A solution (0.45 M) of trans-2-pent-4-en-1-ylcyclopropanol in toluene was treated with methyl 3-methyl-N-(oxomethylene)-L-valinate (1.1 eq) and then DMAP (1 eq). The resulting mixture was heated under reflux for 12 h then cooled to 20° C. H₂O and EtOAc were added, and the organic layer was separated and washed with 1N HCl, brine and dried. Removal of the volatiles afforded a residue that was purified twice by flash chromatography (eluent 0-30% Et₂O/petroleum ether). The first fractions contained methyl 3-methyl-N-({[(1R,2R)-2-pent-4-en-1-ylcyclopropyl]oxy}carbonyl)-L-valinate (38%) as an oil. MS (ES⁺) m/z 298 (M+H)⁺

The later fractions contained methyl 3-methyl-N-({[(1S,2S)-2-pent-4-en-1-ylcyclopropyl]oxy}carbonyl)-L-valinate (28%) as an oil. MS (ES⁺) m/z 298 (M+H)⁺

Step 5: 3-methyl-N-({[(1R,2R)-2-pent-4-en-1-ylcyclopropyl]oxy}carbonyl)-L-valine

A solution (0.1 M) of methyl 3-methyl-N-({[(1R,2R)-2-pent-4-en-1-ylcyclopropyl]oxy}carbonyl)-L-valinate in 2:1 mixture of MeOH/H₂O was treated with LiOH.H₂O (4 eq) and then heated at 60° C. for 4 h. The mixture was cooled and concentrated to half volume, then diluted with EtOAc and acidified with aqueous HCl (1 N). The organic layer was separated and washed with brine then dried. Removal of the volatiles afforded the title compound (98%) as an oil. MS (ES⁺) m/z 284 (M+H)⁺

Intermediates C Intermediate C1 methyl (4R)-4-[(3-chloro-7-methoxyquinoxalin-2-yl)oxy]-L-prolinate hydrochloride

Step 1: 6-methoxyquinoxaline-2,3-diol

A suspension of 4-methoxybenzene-1,2-diamine dihydrochloride in diethyl oxalate (8 eq) was treated with Et₃N (2 eq) and then heated at 150° C. for 2 h. The mixture was cooled and filtered, and then the collected solid was washed with H₂O and EtOH. The residue was dried to give the title compound (69%). MS (ES⁺) m/z 193 (M+H)⁺

Step 2: 3-chloro-6-methoxyquinoxalin-2-ol

A solution (1.53 M) of 6-methoxyquinoxaline-2,3-diol in DMF was treated with SOCl₂ (1 eq) and heated at 110° C. After 1.5 h, the reaction mixture was cooled and poured into aqueous HCl (1 N). The resulting precipitate was filtered and washed with H₂O and Et₂O. The dried solid contained predominantly the title compound as a mixture with 6-methoxyquinoxaline-2,3-diol and 2,3-dichloro-6-methoxyquinoxaline. This material was used directly in the subsequent step. MS (ES⁺) m/z 211 (M+H)⁺

Step 3: 1-tert-butyl 2-methyl (2S,4R)-4-[(3-chloro-7-methoxyquinoxalin-2-yl)oxy]pyrrolidine-1,2-dicarboxylate

A solution (0.35 M) of 3-chloro-6-methoxyquinoxalin-2-ol in NMP was treated with Cs₂CO₃ (1.5 eq) and 1-tert-butyl 2-methyl (2S,4S)-4-{[(4-bromophenyl)sulfonyl]oxy}pyrrolidine-1,2-dicarboxylate (1.1 eq). The resulting mixture was stirred at 50° C. for 18 h, then a further portion (0.1 eq) of 1-tert-butyl 2-methyl (25,45)-4-{[(4-bromophenyl)sulfonyl]oxy}pyrrolidine-1,2-dicarboxylate was added. After stirring for 2 h, the mixture was cooled and diluted with H₂O and EtOAc. The organic phases were washed with aqueous HCl (1 N), saturated aqueous NaHCO₃ and brine. The dried organic phase was concentrated to a residue that was purified by flash-chromatography (0-60% EtOAc/petroleum ether) to give the title compound (35% for two steps) as a solid. MS (ES⁺) m/z 438 (M+H)⁺

Step 4: methyl (4R)-4-[(3-chloro-7-methoxyquinoxalin-2-yl)oxy]-L-prolinate hydrochloride

A solution (0.62 M) of 1-tert-butyl 2-methyl (2S,4R)-4-[(3-chloro-7-methoxyquinoxalin-2-yl)oxy]pyrrolidine-1,2-dicarboxylate in CH₂Cl₂ was treated with a solution (4 M) of HCl in dioxane (5 eq). The mixture was stirred at 20° C. for 2 h, then treated with a solution (4 M) of HCl in dioxane (2 eq). After 5 h, the reaction was judged complete and the mixture was concentrated under reduced pressure. The residue was triturated with Et₂O to give the title compound (95%) as a solid. MS (ES⁺) m/z 338 (M+H)⁺

Example 1 Potassium {[(1R,2S)-1-({[(1aR,5S,8S,10R,22aR)-5-tert-butyl-14-methoxy-3,6-dioxo-1,1a,3,4,5,6,9,10,18,19,20,21,22,22a-tetradecahydro-8H-7,10-methanocyclopropa[18,19][1,10,3,6]dioxadiazacyclononadecino[11,12-b]quinoxalin-8-yl]carbonyl}amino)-2-vinylcyclopropyl]carbonyl}(cyclopropylsulfonyl)azanide

Step 1: methyl 3-methyl-N-({[(1R,2R)-2-pent-4-en-1-ylcyclopropyl]oxy}carbonyl)-L-valyl-(4R)-4-[(3-chloro-7-methoxyquinoxalin-2-yl)oxy]-L-prolinate

A solution (0.2 M) of methyl (4R)-4-[(3-chloro-7-methoxyquinoxalin-2-yl)oxy]-L-prolinate hydrochloride in DMF was treated with 3-methyl-N-({[(1R,2R)-2-pent-4-en-1-ylcyclopropyl]oxy}carbonyl)-L-valine (1.1 eq), DIEA (5 eq) and HATU (1.2 eq). The resulting mixture was stirred at 20° C. for 5 h, then diluted with EtOAc. The organic layer was separated and washed with aqueous HCl (1 N), saturated aqueous NaHCO₃ and brine. The dried organic phase was concentrated under reduced pressure to give a residue that was purified by flash chromatography (eluent 10-30% EtOAc/petroleum ether) to furnish the title compound (96%) as an oil. MS (ES⁺) m/z 604 (M+H)⁺

Step 2: methyl 3-methyl-N-({[(1R,2R)-2-pent-4-en-1-ylcyclopropyl]oxy}carbonyl)-L-valyl-(4R)-4-[(7-methoxy-3-vinylquinoxalin-2-yl)oxy]-L-prolinate

A solution (0.1 M) of methyl 3-methyl-N-({[(1R,2R)-2-pent-4-en-1-ylcyclopropyl]oxy}carbonyl)-L-valyl-(4R)-4-[3-chloro-7-methoxyquinoxalin-2-yl)oxy]-L-prolinate in EtOH was treated with potassium trifluoro(vinyl)borate (1.5 eq) and triethylamine (1.5 eq). The resulting mixture was degassed, then PdCl₂(dppf)-CH₂Cl₂ adduct (0.1 eq) was added. The mixture was heated under reflux for 1 h, then cooled to room temperature and diluted with H₂O and EtOAc. The organic phase was separated, washed with H₂O and brine then dried. Removal of the volatiles afforded a residue that was purified by flash chromatography (20-30% EtOAc/petroleum ether) to give the title compound as a yellow foam that was used directly in the subsequent step. MS (ES⁺) m/z 595 (M+H)⁺

Step 3: methyl (1aR,5S,8S,10R,18E,22aR)-5-tert-butyl-14-methoxy-3,6-dioxo-1,1a,3,4,5,6,9,10,20,21,22,22a-dodecahydro-8H-7,10-methanocyclopropa[18,19][1,10,3,6]dioxadiazacyclononadecino[11,12-b]quinoxaline-8-carboxylate

A solution (0.02 M) of methyl 3-methyl-N-({[(1R,2R)-2-pent-4-en-1-ylcyclopropyl]oxy}carbonyl)-L-valyl-(4R)-4-[(7-methoxy-3-vinylquinoxalin-2-yl)oxy]-L-prolinate in DCE was heated to 80° C. then treated with Zhan 1 catalyst (0.15 eq). The resulting mixture was stirred at 80° C. for 1 h, then cooled to room temperature and concentrated under reduced pressure. The residue was purified by flash chromatography (20-50% EtOAc/petroleum ether) to give the title compound (25% for 2 steps) as a foam. MS (ES⁺) m/z 567 (M+H)⁺

Step 4: methyl (1aR,5S,8S,10R,22aR)-5-tert-butyl-14-methoxy-3,6-dioxo-1,1a,3,4,5,6,9,10,18,19,20,21,22,22a-tetradecahydro-8H-7,10-methanocyclopropa[18,19][1,10,3,6]dioxadiazacyclononadecino[11,12-b]quinoxaline-8-carboxylate

A solution (0.05 M) of methyl (1aR,5S,8S,10R,18E,22aR)-5-tert-butyl-14-methoxy-3,6-dioxo-1,1a,3,4,5,6,9,10,20,21,22,22a-dodecahydro-8H-7,10-methanocyclopropa[18,19][1,10,3,6]dioxadiazacyclononadecino[11,12-b]quinoxaline-8-carboxylate in MeOH/dioxane (1:1 ratio) was treated with Pd/C (8% in weight). The resulting mixture was stirred under atmosphere of hydrogen for 4 h. The catalyst was filtered off, and the filtrate was concentrated under reduced pressure to give the title compound (98%) as a solid. MS (ES⁺) m/z 569 (M+H)⁺

Step 5: (1aR,5S,8S,10R,22aR)-5-tert-butyl-14-methoxy-3,6-dioxo-1,1a,3,4,5,6,9,10,18,19,20,21,22,22a-tetradecahydro-8H-7,10-methanocyclopropa[18,19][1,10,3,6]dioxadiazacyclononadecino[11,12-b]quinoxaline-8-carboxylic acid

A solution (0.1 M) of methyl (1aR,5S,8S,10R,22aR)-5-tert-butyl-14-methoxy-3,6-dioxo-1,1a,3,4,5,6,9,10,18,19,20,21,22,22a-tetradecahydro-8H-7,10-methanocyclopropa[18,19][1,10,3,6]dioxadiazacyclononadecino[11,12-b]quinoxaline-8-carboxylate in a 1:1 mixture of H₂O/THF was treated with LiOH.H₂O (3 eq). The resulting mixture was stirred at 20° C. for 18 h, acidified with aqueous HCl (0.2 M) and diluted with EtOAc. The organic phase was separated, washed with aqueous HCl (0.2 M) and brine then dried. Removal of the volatiles afforded the title compound (98%) as a solid. MS (ES⁺) m/z 555 (M+H)⁺

Step 6: (1aR,5S,8S,10R,22aR)-5-tert-butyl-N-((1R,2S)-1-{[(cyclopropylsulfonyl)amino]carbonyl}-2-vinylcyclopropyl)-14-methoxy-3,6-dioxo-1,1a,3,4,5,6,9,10,18,19,20,21,22,22a-tetradecahydro-8H-7,10-methanocyclopropa[18,19][1,10,3,6]dioxadiazacyclononadecino[11,12-b]quinoxaline-8-carboxamide

A solution (0.1 M) of (1aR,5S,8S,10R,22aR)-5-tert-butyl-14-methoxy-3,6-dioxo-1,1a,3,4,5,6,9,10,18,19,20,21,22,22a-tetradecahydro-8H-7,10-methanocyclopropa[18,19][1,10,3,6]dioxadiazacyclononadecino[11,12-b]quinoxaline-8-carboxylic acid in CH₂Cl₂ was treated with (1R,2S)-1-{[(cyclopropylsulfonyl)amino]carbonyl}-2-vinylcyclopropanaminium chloride (1.3 eq), DIEA (3 eq), DMAP (1.5 eq) and TBTU (1.45 eq). The resulting mixture was stirred at 20° C. for 18 h and then diluted with EtOAc. The solution was washed with aqueous HCl (0.2 M), saturated aqueous NaHCO₃ and brine. The organic phases were dried and concentrated to give a residue that was purified by flash-chromatography (eluent 2.5% MeOH/CH₂Cl₂) to give the title compound (89%) as a solid. ¹³C NMR (100 MHz, DMSO-d₆) δ 172.32, 170.63, 169.04, 159.86, 156.95, 154.74, 148.10, 140.41, 133.55 (2 signals), 128.94, 118.21, 117.58, 105.89, 74.88, 59.75, 58.71, 55.68, 54.13, 54.01, 40.13, 34.49, 34.04, 33.76, 32.68, 30.71, 30.43, 28.55, 27.69, 27.28, 26.38, 21.98, 18.49, 10.67, 5.69, 5.46; MS (ES⁺) m/z 767 (M+H)⁺

GRAZOPREVIR POTASSIUM

Step 7: potassium {[(1R,2S)-1-({[(1aR,5S,8S,10R,22aR)-5-tert-butyl-14-methoxy-3,6-dioxo-1,1a,3,4,5,6,9,10,18,19,20,21,22,22a-tetradecahydro-8H-7,10-methanocyclopropa[18,19][1,10,3,6]dioxadiazacyclononadecino[11,12-b]quinoxalin-8-yl]carbonyl}amino)-2-vinylcyclopropyl]carbonyl}(cyclopropylsulfonyl)azanide

The preceding material was taken up in EtOH and the resulting solution (0.025 M) was cooled to 0° C. A solution (0.02 M) of tert-BuOK (1.5 eq) in EtOH was added leading to the formation of a precipitate. The mixture was stirred at 20° C. for 18 h, then the solid was collected by filtration. This material was washed with EtOH and dried to give the title compound (93%) as a white crystalline solid. MS (ES⁺) m/z 767 (M+H)^{+http://www.google.nl/patents/US8080654}

RAMOSETRON, Antiemetics

Ramosetron (INN),(1-methylindol-3-yl)-[(5R)-4,5,6,7-tetrahydro-3H-benzimidazol-5-yl]methanone,  132036-88-5 cas no

(1-methyl-1H-indol-3-yl)[(5R)-4,5,6,7-tetrahydro-1H-benzimidazol-5-yl]methanone

YM060

• Nasea
• Nor-YM 060
• Ramosetron
• UNII-7ZRO0SC54Y

…………………………………………………………………………………..

HYDROCHLORIDE SALT

hyrochloride salt, cas no 132907-72-3

Yamanouchi (Originator)

Ramosetron (INN) is a serotonin 5-HT₃ receptor antagonist for the treatment of nausea and vomiting.^[1] Ramosetron is also indicated for a treatment of “diarrhea-predominant irritable bowel syndrome in males”.^[2] In India it is marketed under the brand name of“IBset”.
It is only licensed for use in Japan and selected Southeast Asian countries.　In Japan it is sold under the tradename Iribo (イリボー). ^[3] Elsewhere it is commonly sold under the tradename Nasea and in India as Nozia (300 mcg/ml Inj. & 100 mcg Tab.) ^[4]

1.  Fujii Y, Saitoh Y, Tanaka H, Toyooka H (February 2000). “Ramosetron for preventing postoperative nausea and vomiting in women undergoing gynecological surgery”.Anesth. Analg. 90 (2): 472–5. doi:10.1097/00000539-200002000-00043.PMID 10648342.
2. http://www.astellas.com/en/corporate/news/detail/astellas-launches-irribow-for.html
3.  Summary in Japanese. Retrieved on September 4, 2012.
4.  Abridged prescribing information – Nasea (MIMS Philippines). Retrieved on June 13, 2008.
5. Synthesis and 5-HT3 antagonistic activities of 4,5,6, 7-tetrahydrobenzimidazole derivatives
   200th ACS Natl Meet (August 26-31, Washington DC) 1990, Abst MEDI 39

US7652052	1-27-2010	Process for producing ramosetron or its salt
US5576014	11-20-1996	Intrabuccally dissolving compressed moldings and production process thereof
US5496942	3-6-1996	5-substituted tetrahydrobenzimidazole compounds
US5466464	11-15-1995	Intrabuccally disintegrating preparation and production thereof
US5344927	9-7-1994	Tetrahydrobenzimidazole derivatives and pharmaceutical compositions containing same
WO9413284	6-24-1994	NEW USE OF 5-HT3 RECEPTOR ANTAGONISTS

AU 9048890; EP 0381422; JP 1991223278; US 5344927

CN1696128A	Nov 2, 2004	Nov 16, 2005	天津康鸿医药科技发展有限公司	New method for synthesizing Ramosetron Hydrochloride
CN1765896A	Oct 28, 2004	May 3, 2006	北京博尔达生物技术开发有限公司	Novel preparation method of ramosetron hydrochloride

US5496942 *	14 Feb 1994	5 Mar 1996	Yamanouchi Pharmaceutical Co., Ltd.	5-substituted tetrahydrobenzimidazole compounds
US5677326 *	30 Sep 1994	14 Oct 1997	Tokyo Tanabe Company Limited	Indoline compound and 5-HT.sub.3 receptor antagonist containing the same as active ingredient
US7358270	28 Jan 2005	15 Apr 2008	Astellas Pharma Inc.	Treating agent for irritable bowel syndrome
US7683090	18 Oct 2006	23 Mar 2010	Astellas Pharma Inc.	Treating agent for irritable bowel syndrome
US7794748	27 Aug 2004	14 Sep 2010	Yamanouchi Pharmaceutical Co., Ltd.	Stable oral solid drug composition

WO 2010024306

WO 2013005760

WO 2013100701

WO 2011001954

The chemical name of ramosetron is (−)-(R)-5-[(1-methyl-1H-indol-3-yl)carbonyl]-4,5,6,7-tetrahydro-1H-benzimidazole, and it has the structure represented by the formula (II).

It is known that ramosetron or a salt thereof has a potent 5-HT₃ receptor antagonism (Patent Reference 1, Non-patent references 1 and 2), and it is on the market as a preventive or therapeutic agent for digestive symptoms (nausea, emesis) caused by administration of an anti-malignant tumor agent (cisplatin or the like). In addition, a possibility has been reported that ramosetron or a salt thereof may be useful as an agent for treating diarrheal-type irritable bowel syndrome or an agent for improving diarrheal symptoms of irritable bowel syndrome (Patent Reference 1), and its clinical trials are now in progress as an agent for treating diarrheal-type irritable bowel syndrome or an agent for improving diarrheal symptoms of irritable bowel syndrome.

As a process for producing ramosetron or a salt thereof, the following production methods are known.

Patent Reference 1 describes a production method shown by the following Production method A, namely a method for producing a tetrahydrobenzimidazole derivative (V) by allowing a heterocyclic compound (III) to react with a carboxylic acid represented by a formula (IV) or its reactive derivative.

(Production Method A)

(In the formula, X² is a single bond and binds to a carbon atom on the heterocyclic ring represented by Het.)

As an illustrative production method of ramosetron, Patent Reference 1 describes a production method (Production method A-1) in which racemic ramosetron are obtained by using 1-methyl-1H-indole as the compound (III), and N,N-diethyl-4,5,6,7-tetrahydrobenzimidazole-5-carboxamide or N-[(4,5,6,7-tetrahydrobenzimidazol-5-yl)carbonyl]pyrrolidine, which are acid amides, as the reactive derivative of compound (IV), and allowing them to undergo treatment with phosphorus oxychloride (Vilsmeyer reaction), and then their optical resolution is carried out by fractional crystallization using (+)-dibenzoyltartaric acid.

In addition, the Patent Reference 1 exemplifies an acid halide as one of the reactive derivatives of the compound (IV), and also describes another production method of the compound (V) (Production method A-2) in which the heterocyclic compound (III) is condensed with an acid halide of the compound (IV) by the Friedel-Crafts acylation reaction using a Lewis acid as the catalyst. However, illustrative production example of ramosetron by the Friedel-Crafts acylation reaction is not described therein.

Also, a method similar to the Production example A-1 is described in Non-patent References 1 and 2 as a production method of ramosetron.

In addition, Non-patent Reference 3 describes a method for producing ramosetron labeled with ¹¹C, represented by a Production method B. However, it discloses only the methylation step, and does not disclose a production method of nor-YM060 as the starting material.

(Production Method B)

(In the formula, nor-YM060 means (R)-5-[(1H-indol-3-yl)carbonyl]-4,5,6,7-tetrahydro-1H-benzimidazole which was provided by the present applicant, DMF means dimethylformamide.)

• Non-patent Reference 1: Chemical & Pharmaceutical Bulletin, 1996, vol. 44, no. 9, p. 1707-1716
• Non-patent Reference 2: Drugs of the Future, 1992, vol. 17, no. 1, p. 28-29
• Non-patent Reference 3: Applied Radiation and Isotopes, 1995, vol. 46, no. 9, p. 907-910
• Patent Reference 1: JP-B-6-25153

LIU Qing-wen, XU Hao, TIAN Hua, ZHENG Liang-yu, ZHANG Suo-qin
Chemoenzymatic Synthesis of Ramosetron Hydrochloride

2012 Vol. 28 (1): 70-72 [Abstract] ( 1143 ) [HTML 1KB] [PDF 206KB] ( 1052 )
doi:http://www.cjcu.jlu.edu.cn/hxyj/EN/abstract/abstract13356.shtml

…………………………………………………………………………..

The Vilsmeier-type reaction of 1-methylindole (I) with 5 – (1-pyrrolidinocarbonyl) -4,5,6,7-1 H-tetrahydrobenzimidazole hydrochloride (II) and phosphorous oxychloride in 1,2-dichloroethane gives (-5? -. [(1-methyl-3-indolyl) carbonyl] -4,5,6,7-tetrahydro-1H-benzimidazol e (III) Optical resolution of (III) with (+)-dibenzoyltartaric acid (DIBTA) in DMF -H2O, followed by exchange of the salt affords YM060.

………………………………………………….

Ondansetron: 1,2,3 ,9-Tetrahydro-9-methyl-3-[(2-methyl1-H-imidazole-1-yl)methyl]-4H-carbazol-4-one

Granisetron: Endo-1-methyl-N-(9-methyl-9-azabicyclo[3.3.1]non-3-yl)-1H-indazole-3-carboxamide

Tropisetron: Endo-1H-indole-3-carbocylic acid8-methyl-8-azabicyclo[3.2.1]oct-3-yl ester

Dolasetron: 1H-Indole-3 -carboxylic acid (2a, 6a, 8a, 9up)-octahydro-3-oxo-2,6-methano-2H-quinolizin-8-yl Ester

Azasetron: (±)-N-Azabicyclo[2.2.2]oct-3-yl-6-chloro-3,4-dihydro-4-methyl-3-oxo-1,4-benzoxazine-8-carboxamide

Alosetron: 2,3,4,5-Tetrahydro-5-methyl-2-[(5-methyl- 1H-imidazol-4-yl)methyl]-1H-pyrido[4,3-b]indol-1-one

Ramosetron

Galdansetron hydrochloride [USAN]
156712-35-5