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PF 06650833



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CAS 1817626-54-2
Chemical Formula: C18H20FN3O4
Molecular Weight: 361.3734

  • Originator Pfizer
  • Class Anti-inflammatories; Antirheumatics
  • Mechanism of Action Interleukin-1 receptor-associated kinase inhibitors
  • Phase II Rheumatoid arthritis
  • Phase I Lupus vulgaris
  • 01 Aug 2018 Pfizer completes a phase II trial in Rheumatoid arthritis (Treatment-experienced) in USA, Ukraine, Taiwan, Serbia, Russia, Romania, Poland, Mexico, South Korea, Georgia, Bosnia-Herzegovina, Australia, Croatia, Spain, Slovakia, Czech Republic, Hungary, Germany, Bulgaria (PO) (NCT02996500)
  • 28 Jul 2018 No recent reports of development identified for phase-I development in Lupus(In volunteers) in USA (PO, Controlled release)
  • 28 Jul 2018 No recent reports of development identified for phase-I development in Lupus(In volunteers) in USA (PO, Immediate release)
  • PF-06650833 is an inhibitor of Interleukin-1 receptor associated kinase 4 (IRAK4). RAK4 is located proximal to TLR/IL-1 receptors, and in preclinical studies, inhibits downstream signaling from these receptors. The development of novel small molecule inhibitors of this kinase has the potential to lead to new therapeutics to treat diseases such as rheumatoid arthritis, lupus, and lymphomas.

Interleukin-1 receptor associated kinase 4 (IRAK-4) is a serine threonine kinases that plays a key role in innate immune signaling. IRAK-4 is activated by the interleukin (IL-1) family receptors (IL-1R, IL-18R, and IL-33R), as well as the Toll-like receptors (TLRs). Inhibition of IRAK-4 blocks the production of inflammatory cytokines such as type I interferons, tumor necrosis factor (TNF), IL-1, IL-6, and IL-12 that are key drivers of autoimmune and inflammatory diseases. IRAK-4 is an attractive therapeutic target for diseases associated with dysregulated inflammation, such as systemic lupus erythematosus and rheumatoid arthritis.



First Discovery Synthesis of 1

Conditions: (a) LDA (1.2 equiv), TMSCl (1.3 equiv), THF, −60 °C, 30 min; (b) allyl methyl carbonate (1.1 equiv), Pd(OAc)2 (0.05 equiv), THF, 65 °C, 2 h, 73% (2 steps); (c) LiThCN (1.5 equiv), EtMgCl (1.5 equiv), TMSCl (2.0 equiv), THF, −78 °C, 6 h, 90%; (d) LDA (1.8 equiv), NFSI (1.25 equiv), THF, −78 °C, 1 h, 23% (8), 45% (9); (e) pTsOH (0.05 equiv), MeCN, H2O, 90 °C, 2 h, 97%; (f) 3 (0.9 equiv), KHMDS (2.0 equiv), DMF, THF, −10 °C, 30 min, 84%; (g) H2O2 (10 equiv), K2CO3 (4.0 equiv), DMSO, 20 °C, 2 h, 97%.


Image result for PF-06650833

Target: Interleukin-1 receptor associated kinase 4 (IRAK4): This kinase is important in innate immunity, and its inhibition is predicted to be beneficial in treating inflammatory diseases.

Disease: Rheumatoid arthritis, inflammatory bowel disorder

Notes: PF06650833 came from a screening assay that used nuclear magnetic resonance spectroscopy to determine binding between molecular fragments and IRAK4. The initial hit, which bound weakly to IRAK4, was optimized with structure- and property-based medicinal chemistry to generate a series of potent inhibitors, said Katherine Lee, an associate research fellow at Pfizer.


Improvements to Enable the Large Scale Synthesis of 1-{[(2S,3S,4S)-3-Ethyl-4-fluoro-5-oxopyrrolidin-2-yl]methoxy}-7-methoxyisoquinoline-6-carboxamide (PF-06650833)

§ Medicine DesignPfizer Worldwide Research and Development445 Eastern Point Road, Groton, Connecticut 06340, United States
 Chemical Research and DevelopmentPfizer Worldwide Research and Development445 Eastern Point Road, Groton, Connecticut 06340, United States
Org. Process Res. Dev., Article ASAP
DOI: 10.1021/acs.oprd.8b00386
Stephen Wright
Senior Principal Scientist at Pfizer Inc.
New London/Norwich, Connecticut Area
Robert Singer
Robert Singer
Process Chemist -Assoc Research Fellow at Pfizer
New London/Norwich, Connecticut Area

Abstract Image

An improved process for the large scale synthesis of 1-{[(2S,3S,4S)-3-ethyl-4-fluoro-5-oxopyrrolidin-2-yl]methoxy}-7-methoxyisoquinoline-6-carboxamide (1), a candidate currently in clinical development, was developed. Key objectives were to eliminate chromatographic purifications, to maximize the reproducibility of each step, and to improve the yield and efficiency of each step relative to the previous discovery syntheses of 1. This work was focused on improvements to the synthesis of the stereochemically complex lactam 2. Steps of particular concern were the preparation of the unsaturated lactam 6, the cuprate conjugate addition reaction to produce 7, and the conversion of 7 to 8 with a high degree of diastereoselection. The solutions to these challenges have permitted the synthesis of 2 in excess of 100 kg, which in turn has permitted 1 to be prepared in sufficient amounts to support further development.

1 (31.3 kg, 91%, 82% overall) as a white, free-flowing powder.

 1H NMR (500 MHz, DMSO): δ 8.86 (s, 1H), 8.16 (s, 1H), 7.90 (d, J = 5.9 Hz, 1H), 7.84 (br. s., 1H), 7.74 (s, 1H), 7.70 (br. s., 1H), 7.42 (d, J = 5.9 Hz, 1H), 4.90 (dd, J = 5.9, 53.8 Hz, 1H), 4.54 (dd, J = 3.5, 11.1 Hz, 1H), 4.26 (dd, J = 6.4, 11.0 Hz, 1H), 4.13–4.05 (m, 1H), 3.97 (s, 3H), 2.69–2.54 (m, 1H), 1.68–1.53 (m, 2H), 1.02 (t, J = 7.3 Hz, 3H).

13C NMR{1H} (126 MHz, DMSO): δ 171.0 (d, J = 19.4 Hz), 166.4, 158.4, 155.1, 137.7, 131.8, 130.3, 128.4, 120.3, 115.2, 103.2 (d, J = 4.2 Hz), 90.0 (d, J = 179.2 Hz), 66.3, 56.0, 54.1, 42.2 (d, J = 19.4 Hz), 16.4 (d, J = 8.4 Hz), 12.1.

19F NMR (H decoupled, 376 MHz, DMSO-d6): δ −199.26.

LCMS: 362 (MH+).


//////////////PF-06650833, PF 06650833, PF06650833, PF-6650833, PF 6650833, PF6650833.


/////////////////PF-06650833, PF 06650833, Phase 3, Atopic dermatitis, PFIZER, Breakthrough Therapy Designation

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DR ANTHONY MELVIN CRASTO, Born in Mumbai in 1964 and graduated from Mumbai University, Completed his Ph.D from ICT, 1991,Matunga, Mumbai, India, in Organic Chemistry, The thesis topic was Synthesis of Novel Pyrethroid Analogues, Currently he is working with AFRICURE PHARMA, ROW2TECH, NIPER-G, Department of Pharmaceuticals, Ministry of Chemicals and Fertilizers, Govt. of India as ADVISOR, earlier assignment was with GLENMARK LIFE SCIENCES LTD, as CONSUlTANT, Retired from GLENMARK in Jan2022 Research Centre as Principal Scientist, Process Research (bulk actives) at Mahape, Navi Mumbai, India. Total Industry exp 32 plus yrs, Prior to joining Glenmark, he has worked with major multinationals like Hoechst Marion Roussel, now Sanofi, Searle India Ltd, now RPG lifesciences, etc. He has worked with notable scientists like Dr K Nagarajan, Dr Ralph Stapel, Prof S Seshadri, etc, He did custom synthesis for major multinationals in his career like BASF, Novartis, Sanofi, etc., He has worked in Discovery, Natural products, Bulk drugs, Generics, Intermediates, Fine chemicals, Neutraceuticals, GMP, Scaleups, etc, he is now helping millions, has 9 million plus hits on Google on all Organic chemistry websites. His friends call him Open superstar worlddrugtracker. His New Drug Approvals, Green Chemistry International, All about drugs, Eurekamoments, Organic spectroscopy international, etc in organic chemistry are some most read blogs He has hands on experience in initiation and developing novel routes for drug molecules and implementation them on commercial scale over a 32 PLUS year tenure till date Feb 2023, Around 35 plus products in his career. He has good knowledge of IPM, GMP, Regulatory aspects, he has several International patents published worldwide . He has good proficiency in Technology transfer, Spectroscopy, Stereochemistry, Synthesis, Polymorphism etc., He suffered a paralytic stroke/ Acute Transverse mylitis in Dec 2007 and is 90 %Paralysed, He is bound to a wheelchair, this seems to have injected feul in him to help chemists all around the world, he is more active than before and is pushing boundaries, He has 100 million plus hits on Google, 2.5 lakh plus connections on all networking sites, 100 Lakh plus views on dozen plus blogs, 227 countries, 7 continents, He makes himself available to all, contact him on +91 9323115463, email, Twitter, @amcrasto , He lives and will die for his family, 90% paralysis cannot kill his soul., Notably he has 38 lakh plus views on New Drug Approvals Blog in 227 countries...... , He appreciates the help he gets from one and all, Friends, Family, Glenmark, Readers, Wellwishers, Doctors, Drug authorities, His Contacts, Physiotherapist, etc He has total of 32 International and Indian awards

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