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Wednesday, 20 January 2016

Ibudilast



Ibudilast.svg
IBUDILAST, MN 166
AV-411
KC-404
MN-166
2-methyl-1-(2-propan-2-ylpyrazolo[1,5-a]pyridin-3-yl)propan-1-one
1-(2-isopropylpyrazolo[1,5-a]pyridin-3-yl)-2-methylpropan-1-one
KYORIN Kyorin Seiyaku Kk……….INNOVATOR
Properties: Crystals from hexane, mp 53.5-54°. Slightly sol in water, freely sol in organic solvents. LD50 i.v. in mice: 260 mg/kg (Irikura, 1973).
Melting point: mp 53.5-54°
Toxicity data: LD50 i.v. in mice: 260 mg/kg (Irikura, 1973)
Therap-Cat: Antiallergic; antiasthmatic; vasodilator (cerebral).

Ibudilast is an anti-inflammatory and neuroprotective oral agent which shows an excellent safety profile at 60 mg/day and provides significantly prolonged time-to-first relapse and attenuated brain volume shrinkage in patients with relapsing-remitting (RR) and/or secondary progressive (SP) multiple sclerosis (MS). Ibudilast is currently in development in the U.S. (codes: AV-411 or MN-166), but is approved for use as an antiinflammatory in Japan.
CAS: 50847-11-5, Ibudilastum, Ketas, KC-404, MN-166, Ke Tas
Molecular Formula:C14H18N2O
Molecular Weight:230.30552 g/mol
 Ibudilast
Ibudilast is a leukotriene antagonist and phosphodiesterase inhibitor which has been commercialized in Japan and other parts of Asia for over 15 years as capsules for the treatment of bronchial asthma and cerebrovascular disturbances. In 2000, the product was launched for the topical treatment of allergic conjunctivitis. At present, the drug is undergoing phase II trials at MediciNova for the oral treatment of multiple sclerosis (MS), for the treatment of medication overuse headache (MOH), for the treatment of diabetic neuropathic pain, for the treatment of methamphetamine addiction and for the treatment of opioid withdrawal.
Early clinical trials are ongoing for the treatment of amyotrophic lateral sclerosis as an adjunt to riluzole.MediciNova and the University of Colorado had been evaluating the product in preclinical studies for the treatment of post-traumatic brain injury; however, no recent development has been reported for this research.Ibudilast exhibits antiplatelet properties mainly by inhibiting phosphodiesterase V (PDE V), which in turn potentiates antiplatelet function of endothelium-derived nitric oxide (NO). The compound has also been shown to suppress hippocampal apoptosis induced by amyloid beta hypoxia.
 

ibudilast.png

Ibudilast (development codes: AV-411 or MN-166) is an antiinflammatory drug used mainly in Japan, which acts as aphosphodiesterase inhibitor, inhibiting the PDE-4 subtype to the greatest extent,[1] but also showing significant inhibition of other PDE subtypes.[2][3]
Ibudilast has bronchodilatorvasodilator [4] and neuroprotective effects,[5][6] and is mainly used in the treatment of asthma andstroke.[7] It inhibits plateletaggregation,[8] and may also be useful in the treatment of multiple sclerosis.[9]
Ibudilast crosses the blood–brain barrier and suppresses glial cell activation. This activity has been shown to make ibudilast useful in the treatment ofneuropathic pain and it not only enhances analgesia produced by opioid drugs, but also reduces the development oftolerance.[10]
It may have some use reducing methamphetamine[11] and alcohol[12] addiction.
It may have some use reducing methamphetamine addiction.[11]
Avigen has identified the potential of ibudilast (AV-411) for the treatment of neuropathic pain and other neurological indications, including opiate withdrawal. As an inhibitor of glial cells, ibudilast can deactivate these cells which produce various chemicals, including proinflammatory cytokines, in response to nerve damage or viral infection to amplify and maintain pain. Preclinical evaluation to date indicates that it reverses the painful sensory abnormality allodynia in chemotherapy- and trauma-induced neuropathic pain models.
Originator Kyorin and Banyu Pharmaceutical (now MSD KK following the merger of Banyu and Schering-Plough KK in 2010) have been developing ibudilast under a collaborative agreement. MediciNova obtained exclusive, worldwide rights outside of Japan, China, Taiwan and South Korea from Kyorin in October 2004 to develop and commercialize the compound for MS. In 2012, a codevelopment agreement was signed between MediciNova and the University of Colorado for the treatment of post-traumatic brain injury.
Sixteenth revised Japanese Pharmacopoeia chemicals, etc. IBUDILAST  Ibudilast C14H18N2O: 230.31 [ 50847-11-5 ] that this product was dried when to quantify, including ibudilast (C14H18N2O) 98.5 ~ 101.0%.


EXAMPLE 1 Synthesis of 2-isopropyl-3-is0butyrylpyrazolo[1,5-a] pyridine (KC404) A mixture of 1-amino-Z-methylpyridinium iodide g.), isobutyric anhydride (500 g.) and K CO (81 g.) was refluxed for 8 hr. After cooling, the precipitated crystals were filtered off and water was added to the filtrate, The solution was made basic to pH 11 with K CO’ and extracted with ethyl acetate (1000 ml.). The extract’was washed with water (400 ml.), dried over Na SO and concentrated under reduced pressure. The residue was distilled to give 58 g. of colorless crystalline product, hp, 110- 175 (7.5 mm. Hg). Recrystallization from hexane gave colorless prisms, melting point 53.554.
Analysis- Calcd.: C, 73.01; H, 7.88; N, 12.17 Found: C, 72.86; H, 7.94; N, 12.09
CLIP
PATENT
FIG. 6 is a synthetic reaction scheme illustrating one approach for preparing (S)-AV1013; the approach employs chiral chromatography of an N-protected form of the racemate as described in detail in Example 1.
FIG. 7 demonstrates additional reaction schemes for synthesizing (S)-AV1013.



Example 1Synthesis of (S)-2-amino-1-(2-isopropylpyrazolo[1,5-a]pyridin-3-yl)propan-1-one hydrochloride
(S)-2-Amino-1-(2-isopropylpyrazolo[1,5-a]pyridin-3-yl)propan-1-one hydrochloride (also referred to herein as S-AV1013.HCl) was prepared on a preparative scale using two different routes to obtain the intermediate isopropylpyrazolo[1,5-a]pyridine (IPPP). In the first approach (method 1), ibudilast was employed as the starting material to obtain IPPP; an alternate synthetic approach (method 2) employed ibudilast acid as the starting material.
Step 1Method 1Preparation of Isopropylpyrazolo[1,5-a]pyridine (IPPP) from ibudilast
Figure US08119657-20120221-C00002
A 5 L 3-neck round-bottom flask was equipped with a mechanical stirrer, thermocouple, heating mantle and a Y-adapter with a nitrogen inlet. The flask was charged with water (350 mL, USP), concentrated sulfuric acid (350 mL) and ibudilast (3-isobutyryl-2-isopropylpyrazolo[1,5-a]pyridine) (140 g, 0.608 mol). The flask was purged with nitrogen, and the mixture was stirred while it was heated to 135° C. An aliquot was removed for HPLC analysis, which showed that all starting material was consumed after 5 hours at 135° C., so the mixture was allowed to cool to room temperature overnight. The mixture was cooled in an ice bath, and water (1400 mL, USP) was added over 10 min, with the temperature maintained below 25° C. With continuous cooling in an ice bath, the mixture was neutralized by adding sodium hydroxide (50% w/w aq., 1150 mL) dropwise, with the temperature maintained below 25° C. Ethyl acetate (250 mL) was added, and the layers were separated. The aqueous layer was washed with ethyl acetate (2×300 mL). The combined ethyl acetate extracts were washed sequentially with 250 mL portions of saturated aqueous sodium bicarbonate and saturated aqueous sodium chloride, then dried over anhydrous sodium sulfate for 30 minutes. Activated carbon (20 g) and silica (60 g) were added and stirred before filtering over a pad of Celite. The filtrate was concentrated under reduced pressure to obtain 96.5 g of IPPP (2-isopropyl-pyrazolo[1,5-a]pyridine, 99% crude yield, 99.6 area % pure by HPLC) as an amber oil.
1H-NMR (CDCl3) δ 1.4 (d, 6H), 3.2 (m, 1H), 6.3 (s, 1H), 6.6 (t, 1H), 7.0 (m, 1H), 7.4 (d, 1H), 8.4 (d, 1H). HPLC: RT=9.1 min (99.6 area %).

CLIP
Ibudilast (3-isobutyryl-2-isopropylpyrazolo[l,5-α]pyridine) is a small molecule drug that has been used for many years in Japan and Korea for the treatment of bronchial asthma as well as for treatment of cerebrovascular disorders such as post-stroke dizziness. It is sold in these countries under the tradename, Ketas®. Marketed indications for ibudilast in Japan include its use as a vasodilator, for treating allergy, eye tissue regeneration, ocular disease, and treatment of allergic ophthalmic disease (Thompson Current Drug Reports). Its use in the treatment of both chronic brain infarction (ClinicalTrials.gov) and multiple sclerosis (News.Medical.Net; Pharmaceutical News, 2 Aug 2005) is currently being explored in separate, ongoing clinical trials.
The mechanisms of action of ibudilast have been widely explored. Its role as a non-selective inhibitor of cyclic nucleotide phosphodiesterase (PDE) has been described
(Fujimoto, T., et al., J. of Neuroimmunology, 95 (1999) 35-92). Additionally, ibudilast has been reported to act as an LTD4 antagonist, an anti-inflammatory, a PAF antagonist, and a vasodilatator agent (Thompson Current Drug Reports). Ibudilast is also thought to exert a neuroprotective role in the central nervous system of mammals, presumably via suppression of the activation of glial cells (Mizuno et al. (2004) Neuropharmacology 46: 404-411). New uses for ibudilast continue to be explored.http://www.google.com/patents/WO2007146087A2?cl=en
PATENT
IBUDILAST
Ibudilast is a small molecule drug (molecular weight of 230.3) having the structure shown below.
Figure imgf000011_0001
Ibudilast is also found under ChemBank ID 3227, CAS # 50847-1 1-5, and Beilstein Handbook Reference No. 5-24-03-00396. Its molecular formula corresponds to [Ci4HIgN2O]. Ibudilast is also known by various chemical names which include 2- methyl-l-(2-(l-methylethyI)pyrazolo(l,5-a)pyridin-3-yl)l-propanone; 3-isobutyryl-2- isopropylpyrazolo(l,5-a)pyridine]; and l-(2-isopropyl-pyrazolo[l,5-a]pyridin-3-yl)-2- methyl-propan-1-one. Other synonyms for ibudilast include Ibudilastum (Latin), BRN 0656579, KC-404, and the brand name Ketas®. Ibudilast, as referred to herein, is meant to include any and all pharmaceutically acceptable salt forms thereof, prodrug forms (e.g., the corresponding ketal), and the like, as appropriate for use in its intended formulation for administration.
Ibudilast is a non-selective nucleotide phosphodiesterase (PDE) inhibitor (most active against PDE-3 and PDE-4), and has also been reported to have LTD4 and PAF antagonistic activities. Its profile appears effectively anti-inflammatory and unique in comparison to other PDE inhibitors and anti-inflammatory agents. PDEs catalyze the hydrolysis of the phosphoester bond on the 3 -carbon to yield the corresponding 5′- nucleotide monophosphate. Thus, they regulate the cellular concentrations of cyclic nucleotides. Since extracellular receptors for many hormones and neurotransmitters utilize cyclic nucleotides as second messengers, the PDEs also regulate cellular responses to these extracellular signals. There are at least eight classes of PDEs: Ca2+/calmodul in-dependent PDEs (PDEl); cGMP-stimulated PDEs (PDE2); cGMP- inhibited PDEs (PDE3); cAMP-specific PDEs (PDE4); cGMP-binding PDEs (PDE5); photoreceptor PDEs (PDE6); high affinity, cAMP-specific PDEs (PDE7); and high affinity cGMP-specific PDEs (PDE9).
SYNTHESIS
DE 2315801; FR 2182914; JP 7714799, WO 0196278
By condensation of 1-amino-2-methylpyridinium iodide (I) with isobutyric anhydride (II) by means of K2CO3 at reflux temperature.
Patent
PATENT
2-methyl -l- [2- (l- methylethyl) – pyrazolo [l, 5_a] pyrimidine _3_ yl] _1_ acetone (ibudilast, generic drug name: IBUDILAST ) is an anti-allergic asthma drugs, anti-leukotrienes can twist and platelet-activating factor, promote the secretion of mucus in the respiratory tract, respiratory cilia function, enhance the role of prostacyclin, increase cerebral blood flow, improve brain metabolism. For the treatment of bronchial asthma, sequelae of cerebral embolism, cerebral arteriosclerosis.
 ibudilast preparation methods are mainly the following two:
 Method a: (The Jourrtal of Organic Chemistry, 1968, 33, 3766 ~3770) Synthesis Road
Lines are as follows:

Figure CN102617579AD00041
 The route to 2-picoline as starting material to give amino-2-methyl-pyridine iodide I-, after pyrimidine, the role of isobutyryl chloride to give the title compound. The final product obtained by this route need be purified by column chromatography, thereby increasing the difficulty of the operation, in addition to column chromatography, eluent used larger benzene toxicity, is not suitable for industrial production.
 Method II: (Journal of the American Chemical Society, 2005,127, 751-760) co
A route is as follows:

Figure CN102617579AD00042
The route to 2-picoline as starting material to obtain the sulfamic acid, potassium iodide I- amino-2-picoline under the action of potassium carbonate, then with isobutyric anhydride to give the title compound effect. This route of the first-stage reaction process locked, the yield is low, is not suitable for industrial production.
 so there ibudilast conventional method for preparing the operational difficulties or low yield, making it impossible to achieve industrial production problems.
DETAILED DESCRIPTION IX: with a specific embodiment of the present embodiment is one of one to eight different points: in the second step of the recrystallization specific operation is as follows: First, the collected fractions was cooled to 10 ° c~25 ° C, to give a pale yellow solid, and then n-hexane was added to the pale yellow solid, and the temperature was raised to 50 ° C~68 ° C, at a temperature of 50 ° C~68 ° C incubation 5min~IOmin, then cooled to 10 ° C~ 25 ° C, and at a temperature of 10 ° C~25 ° C incubated O. 5h~Ih, and finally filtered to obtain ibudilast; the volume of the pale yellow solid quality and hexane ratio of Ig: (ImL~2mL), to obtain ibudilast.
PAPER
Ibudilast [1-(2-isopropylpyrazolo[1,5-a]pyridin-3-yl)-2-methylpropan-1-one] is a nonselective phosphodiesterase inhibitor used clinically to treat asthma. Efforts to selectively develop the PDE3- and PDE4-inhibitory activity of ibudilast led to replacement of the isopropyl ketone by a pyridazinone heterocycle. Structure–activity relationship exploration in the resulting 6-(pyrazolo[1,5-a]pyridin-3-yl)pyridazin-3(2H)-ones revealed that the pyridazinone lactam functionality is a critical determinant for PDE3-inhibitory activity, with the nitrogen preferably unsubstituted. PDE4 inhibition is strongly promoted by introduction of a hydrophobic substituent at the pyridazinone N(2) centre and a methoxy group at C-7′ in the pyrazolopyridine. Migration of the pyridazinone ring connection from the pyrazolopyridine 3′-centre to C-4′ strongly enhances PDE4 inhibition. These studies establish a basis for development of potent PDE4-selective and dual PDE3/4-selective inhibitors derived from ibudilast.
Image for unlabelled figure


UPDATE AS ON JAN 2016
…………..MediciNova’s ibudilast gets FDA rare paediatric disease status to treat Krabbe disease 
MediciNova has received rare paediatric disease status from the US Food and Drug Administration (FDA) for its MN-166 (ibudilast) to treat Type 1 Early Infantile Krabbe disease.

References

  1.  Huang Z, Liu S, Zhang L, Salem M, Greig GM, Chan CC, Natsumeda Y, Noguchi K. Preferential inhibition of human phosphodiesterase 4 by ibudilast. Life Sciences. 2006 May 1;78(23):2663-8.
  2.  Suzumura A, Ito A, Yoshikawa M, Sawada M. Ibudilast suppresses TNFalpha production by glial cells functioning mainly as type III phosphodiesterase inhibitor in the CNS. Brain Research. 1999 Aug 7;837(1-2):203-12.
  3.  Gibson LC, Hastings SF, McPhee I, Clayton RA, Darroch CE, Mackenzie A, Mackenzie FL, Nagasawa M, Stevens PA, Mackenzie SJ. The inhibitory profile of Ibudilast against the human phosphodiesterase enzyme family.European Journal of Pharmacology. 2006 May 24;538(1-3):39-42.
  4.  Kishi Y, Ohta S, Kasuya N, Sakita S, Ashikaga T, Isobe M. Ibudilast: a non-selective PDE inhibitor with multiple actions on blood cells and the vascular wall. Cardiovascular Drug Reviews. 2001 Fall;19(3):215-25.
  5.  Mizuno T, Kurotani T, Komatsu Y, Kawanokuchi J, Kato H, Mitsuma N, Suzumura A. Neuroprotective role of phosphodiesterase inhibitor ibudilast on neuronal cell death induced by activated microglia.Neuropharmacology. 2004 Mar;46(3):404-11.
  6.  Yoshioka M, Suda N, Mori K, Ueno K, Itoh Y, Togashi H, Matsumoto M. Effects of ibudilast on hippocampal long-term potentiation and passive avoidance responses in rats with transient cerebral ischemia.Pharmacological Research. 2002 Apr;45(4):305-11.
  7.  Wakita H, Tomimoto H, Akiguchi I, Lin JX, Ihara M, Ohtani R, Shibata M. Ibudilast, a phosphodiesterase inhibitor, protects against white matter damage under chronic cerebral hypoperfusion in the rat. Brain Research. 2003 Nov 28;992(1):53-9.
  8.  Rile G, Yatomi Y, Qi R, Satoh K, Ozaki Y. Potentiation of ibudilast inhibition of platelet aggregation in the presence of endothelial cells.Thrombosis Research. 2001 May 1;102(3):239-46.
  9.  Feng J, Misu T, Fujihara K, Sakoda S, Nakatsuji Y, Fukaura H, Kikuchi S, Tashiro K, Suzumura A, Ishii N, Sugamura K, Nakashima I, Itoyama Y. Ibudilast, a nonselective phosphodiesterase inhibitor, regulates Th1/Th2 balance and NKT cell subset in multiple sclerosis. Multiple Sclerosis. 2004 Oct;10(5):494-8.
  10. Ledeboer A, Hutchinson MR, Watkins LR, Johnson KW. Ibudilast (AV-411). A new class therapeutic candidate for neuropathic pain and opioid withdrawal syndromes. Expert Opinion on Investigational Drugs. 2007 Jul;16(7):935-50.
  11.  http://www.huffingtonpost.com/2013/04/03/meth-addiction-cure-ucla-ibudilast_n_2863126.html?utm_hp_ref=mostpopular#slide=more268305
  12.  http://onlinelibrary.wiley.com/doi/10.1111/adb.12106/abstrac
SEE……Synthesis technology of ibudilast
Shandong Huagong (2014), 43, (8), 29-30. Publisher: (Shandong Huagong Bianjibu, ) CODEN:SHHUA4 ISSN:1008-021X.

Literature References:
Leukotriene D4 antagonist. Prepn: T. Irikura et al., DE 2315801eidem, US3850941 (1973, 1974 both to Kyorin).
Pharmacology and antiallergic activity: K. Nishino et al., Jpn. J. Pharmacol. 33,267 (1983); H. Nagai et al., ibid. 1215.
In vitro cerebral vasodilating activity: M. Ohashi et al., Arch. Int. Pharmacodyn.280, 216 (1986);
in vivo activity: W. M. Armstead et al., J. Pharmacol. Exp. Ther. 244, 138 (1988).
Bronchodilating activity in animals: S. Mue et al., Arch. Int. Pharmacodyn.283,153 (1986).
Antiplatelet activity in animals: M. Ohashi et al., ibid. 321; M. Ohashi et al., Gen. Pharmacol. 17, 385 (1986).
PATENTSUBMITTEDGRANTED
Method for treating neuropathic pain and associated syndromes [US7534806]2006-07-202009-05-19
Synergistic combination [US2006205806]2006-09-14
Pharmaceutical composition of a pde4 or pde 3/4 inhibitor and histamine receptor antagonist [US2005112069]2005-05-26
Methods and reagents for the treatment of immunoinflammatory disorders [US2005119160]2005-06-02
Methods of inducing ovulation using a non-polypeptide camp level modulator [US7507707]2005-07-072009-03-24
Methods and reagents for the treatment of immunoinflammatory disorders [US2005192261]2005-09-01
Synergistic combination [US7056936]2004-02-192006-06-06
Methods for the treatment of respiratory diseases and conditions with a selective iNOS inhibitor and a PDE inhibitor and compositions therefor [US2004087653]2004-05-06
Remedies for multiple sclerosis [US6395747]2002-05-28
Combination [US2005014762]2005-01-20
 PATENTFILING DATEPUBLICATION DATEAPPLICANTTITLE
US4097483Aug 31, 1976Jun 27, 1978Kyorin Pharmaceutical Co., Ltd.Pyrazolo 1,5-a!pyridines
US7585875 *Jun 6, 2007Sep 8, 2009Avigen, Inc.Phosphodiesterase inhibitors; neuropathic pain, inflammation, opioid dependence or withdrawal; 2-amino-1-(2-isopropylpyrazolo[1,5-a]pyridin-3-yl)propan-1-one for example
US20070015924Jun 15, 2006Jan 18, 2007Cardiome Pharma Corp.stereoselective preparation of aminocyclohexyl ether compounds such as trans-(1R,2R)-aminocyclohexyl ether compounds and/or trans-(1S,2S)-aminocyclohexyl ether compounds; useful in treating arrhythmias
US20080070912Jun 6, 2007Mar 20, 2008Avigen, Inc.Phosphodiesterase inhibitors; neuropathic pain, inflammation, opioid dependence or withdrawal; 2-amino-1-(2-isopropylpyrazolo[1,5-a]pyridin-3-yl)propan-1-one for example
US20090062330Jul 8, 2008Mar 5, 2009Medicinova, Inc.Treatment of progressive neurodegenerative disease with ibudilast
US20090318437 *Jun 10, 2009Dec 24, 2009Gaeta Federico C ASUBSTITUTED PYRAZOLO[1,5-a] PYRIDINE COMPOUNDS AND THEIR METHODS OF USE
WO2007142924A1May 29, 2007Dec 13, 2007Avigen IncIbudilast for inhibiting macrophage migration inhibitory factor (mif) activity
WO2007146087A2*Jun 6, 2007Dec 21, 2007Avigen IncSUBSTITUTED PYRAZOLO [1,5-α] PYRIDINE COMPOUNDS AND THEIR METHODS OF USE
WO2010151551A1*Jun 22, 2010Dec 29, 2010Medicinova, Inc.ENANTIOMERIC COMPOSITIONS OF 2-AMINO-1-(2-ISOPROPYLPYRAZOLO[1,5-a]PYRIDIN-3-YL)PROPAN-1-ONE AND RELATED METHODS
US8119657Jun 22, 2010Feb 21, 2012Medicinova, Inc.Enantiomeric compositions of 2-amino-1-(2-isopropylpyrazolo[1,5-α]pyridin-3-yl)propan-1-one and related methods
PATENTFILING DATEPUBLICATION DATEAPPLICANTTITLE
WO2003104178A1*Jun 6, 2003Dec 18, 2003Cortical Pty LtdNapththalene derivatives which inhibit the cytokine or biological activity of macrophage migration inhibitory factor (mif)
WO2003104203A1*Jun 6, 2003Dec 18, 2003Cortical Pty LtdTherapeutic molecules and methods-1
WO2004058713A1*Dec 18, 2003Jul 15, 2004Jason ChybaDifferential tumor cytotoxocity compounds and compositions
WO2005058304A1*Dec 17, 2004Jun 30, 2005Cortical Pty LtdImplantable device containing inhibitor of macrophage migration inhibitory factor
WO2006045505A1*Oct 19, 2005May 4, 2006Novartis AgMif-inhibitors
WO2006108671A1*Apr 13, 2006Oct 19, 2006Novartis Ag3,4-dihydro-benzo[e][1,3]oxazin-2-ones
IBUDILAST
Ibudilast.svg
SYSTEMATIC (IUPAC) NAME
2-methyl-1-(2-propan-2-ylpyrazolo[1,5-a]pyridin-3-yl)propan-1-one
CLINICAL DATA
AHFS/DRUGS.COMInternational Drug Names
IDENTIFIERS
CAS NUMBER50847-11-5 Yes
ATC CODER03DC04
PUBCHEMCID: 3671
IUPHAR/BPS7399
DRUGBANKDB05266 
CHEMSPIDER3543 
UNIIM0TTH61XC5 
KEGGD01385 Yes
CHEMBLCHEMBL19449 
CHEMICAL DATA
FORMULAC14H18N2O
MOLECULAR MASS230.31 g/mol
Keywords: Antiallergic; Antiasthmatic (Nonbronchodilator); Leukotriene Antagonist; Vasodilator (Cerebral).
////////////////////
CC(C)C1=NN2C=CC=CC2=C1C(=O)C(C)C

Tuesday, 19 January 2016

Baricitinib


File:Baricitinib.svg
ChemSpider 2D Image | Baricitinib | C16H17N7O2S
Baricitinib

NDA submitted jan 2016
2-[1-ethylsulfonyl-3-[4-(7H-pyrrolo[2,3-d]pyrimidin-4-yl)pyrazol-1-yl]azetidin-3-yl]acetonitrile,
3-Azetidineacetonitrile, 1-(ethylsulfonyl)-3-[4-(7H-pyrrolo[2,3-d]pyrimidin-4-yl)-1Hpyrazol-1-yl]-
2-(3-(4-(7H-pyrrolo[2,3-d]pyrimidin-4-yl)-1H-pyrazol-1-yl)-1-(ethylsulfonyl)azetidin-3-yl)acetonitrile

2-(3-(4-(7H-pyrrolo[2,3-d]pyrimidin-4-yl)-1H-pyrazol-1-yl)-1-(ethylsulfonyl)azetidin-3-yl)acetonitrile
3-Azetidineacetonitrile, 1-(ethylsulfonyl)-3-[4-(7H-pyrrolo[2,3-d]pyrimidin-4-yl)-1H-pyrazol-1-yl]-
2-(3-(4-(7H-pyrrolo[2,3-d]pyrimidin-4-yl)-1H-pyrazol-1-yl)-1-(ethylsulfonyl)azetidin-3-yl)acetonitrile
For the treatment of rheumatoid arthritis and diabetic kidney disease
Incyte Corporation INNOVATOR
MF C16H17N7O2S
MW 371.4
SPONSOR Eli Lilly and Company
CODE  LY3009104, INCB028050
CAS  1187594-09-7
WO 2009114512

2-[3-(4-{7H-pyrrolo[2,3-d]pyrimidin-4-yl}-1H-pyrazol- 1-yl)-1-(ethylsulfonyl)azetidin-3-yl]acetonitrile (baricitinib)  FREE FORM
m.p. 193–195 °C;
IR: 3203, 3113, 2998, 2847, 2363, 1584, 1328, 1137 cm–1.
Anal. calcd for C16H17N7 O2 S: C, 51.74; H, 4.61; N, 26.40; found: C, 51.91; H, 4.49; N, 26.57%. MS (m/z): 372 [M + H]+;
1 H NMR (300 MHz, DMSO-d6 ): δ 1.25 (t, J = 7.3 Hz, 3H), 3.23 (m, J = 7.3 Hz, 2H), 3.69 (s, 2H), 4.24 (d, J = 9.0 Hz, 2H), 4.61 (d, J = 9.0 Hz, 2H), 7.08 (s, 1H), 7.62 (s, 1H), 8.47 (s, 1H), 8.71 (s, 1H), 8.92 (s, 1H), 12.12 (s, 1H);
13C NMR (125 MHz, DMSO-d6 ): δ 7.4, 24.9, 39.3, 43.4, 58.5, 99.9, 113.0, 116.6, 126.9, 129.5, 139.9, 149.3, 150.9, 152.2.
REF  Journal of Chemical Research, Volume 40, Number 4, April 2016,pp. 205-208(4)



ChemSpider 2D Image | {1-(Ethylsulfonyl)-3-[4-(1H-pyrrolo[2,3-d]pyrimidin-4-yl)-1H-pyrazol-1-yl]-3-azetidinyl}acetonitrile phosphate (1:1) | C16H20N7O6PS

Baricitinib phosphate

{1-(Ethylsulfonyl)-3-[4-(1H-pyrrolo[2,3-d]pyrimidin-4-yl)-1H-pyrazol-1-yl]-3-azetidinyl}acetonitrile phosphate (1:1)


1187595-84-1, C16H20N7O6PS, 469.41


  • Originator Incyte Corporation
  • Developer Eli Lilly; Incyte Corporation
  • Class Acetonitriles; Antipsoriatics; Antirheumatics; Azetidines; Pyrazoles; Pyrimidines; Pyrroles; Small molecules
  • Mechanism of Action Janus kinase 1 inhibitors; Janus kinase-2 inhibitors

Highest Development Phases

  • Preregistration Rheumatoid arthritis
  • Phase II Atopic dermatitis; Diabetic nephropathies; Psoriasis; Systemic lupus erythematosus

Most Recent Events

  • 01 Jul 2016 Eli Lilly completes a phase I trial in Healthy volunteers in China (PO) (NCT02758613)
  • 09 Jun 2016 Efficacy and adverse events data from the RA-BEYOND phase III trial in Rheumatoid arthritis 





The Janus kinase (JAK) is a family of four tyrosine receptor kinases that play a pivotal role in cytokine receptor signalling pathways via their interaction with signal transducers and
activators of transcription proteins. The four JAK family members are Janus kinase 1 (JAK1), Janus kinase 2 (JAK2), Janus kinase 3 (JAK3) and tyrosine kinase (TYK2), whose
lengths range from 120 to 140 kDa. It has been shown that JAK2 activation may be critical for tumour growth and progression,indicating its selection as a therapeutic target. Moreover, since JAK3 is required for immune cell development, targeting JAK3 could be a useful strategy for generating a novel class of immunosuppressant drugs. JAK1 and TYK2 have been implicated in disease and immune suppression.
Over the past decade there have been extensive efforts to identify and design novel small-molecule JAK inhibitors with varied profiles of subtype selectivity to address unmet medical needs  Ruxolitinib is a Janus kinase inhibitor with selectivity for subtypes JAK1 and JAK2. It was approved by the U.S. Food and Drug Administration (FDA) for the treatment
of intermediate or high-risk myelofibrosis in November 2011.
Selective inhibitors of JAK are viewed as having considerable potential as disease-modifying anti-inflammatory drugs for the treatment of rheumatoid arthritis. Tofacitinib, which was the first oral non-biological disease-modifying antirheumatic drug, was approved for the management of rheumatoid arthritis (RA) at the end of 2012. Baricitinib and filgotinib are beingmevaluated in phase III and phase II clinical trials respectively for the treatment of rheumatoid arthritis. 
Baricitinib (also known as LY3009104 or INCB028050) is a novel and potent small molecule inhibitor of the Janus kinase family of enzymes with selectivity for JAK1 and JAK2. In in vitro studies baricitinib inhibited JAK1 and JAK2 in the low nanomolar range, while it demonstrated low inhibitory activity for JAK3 and moderate activity for TYK2.9–13 The data from two phase III studies showed that baricitinib can achieve impressive responses in RA patients who have not responded well to established therapies.
Therefore, improvement in the preparation of baricitinib is of practical significance.
1 L. Tan, K. Akahane, ET AL J. Med. Chem., 2015, 58, 6589.
2 J.J. Kulagowski, ET AL, J. Med. Chem., 2012, 55, 5901.
3 J.F. Kadow, ET AL , J. Med. Chem.,2012, 55, 2048.
4 Q. Su, ET AL  J. Med. Chem., 2014, 57, 144.
5 J.D. Clark, ET AL  J. Med. Chem., 2014, 57, 5023.
6 P. Norman, Expert. Opin. Investig. Drugs, 2014, 23, 1067.
7 L.J. Farmer, ET AL J. Med. Chem., 2015, 58,7195.
8 S.C. Meyer and R.L. Levine, Clin. Cancer. Res., 2014, 20, 2051.


Baricitinib (formerly INCB28050, LY3009104)[1] is an oral JAK1 and JAK2 inhibitor.
Baricitinib is in Phase III development by Eli Lilly and Incyte as a potential treatment for rheumatoid arthritis.[2] It is in Phase II development as a potential treatment for psoriasis and diabetic nephropathy. The related compound in JAK inhibitor is Tofacitinib, currently approved for the treatment of rheumatoid arthritis (RA) in the United States.
Baricitinib.png
The companies announced 52-week data from a Phase IIb study of baricitinib at the European Congress of Rheumatology meeting in Madrid which showed that clinical improvements previously observed at week 24 were sustained for the full year in RA patients. Specifically, 49% of patients were ACR50 responders (ie a 50% improvement in their condition) after 52 weeks compared to 41% at week 24. For the full year, 21% reached ACR70 compared with 27% after 24 weeks.
To date, baricitinib, an orally administered selective JAK1 and JAK2 inhibitor,  has demonstrated “an acceptable safety profile and side effects have generally been straightforward to manage”, said Oxford University’s Peter Taylor. He added that “these encouraging findings support further investigation of this new drug in RA”.
Baricitinib is already in Phase III for RA and in Phase II for psoriasis and diabetic nephropathy.
WO2009114512, also to Incyte, discloses azetidine and cyclobutane derivatives of the general structure shown below as JAK inhibitors.
Baricitinib (also known as LY3009104 or INCB28050) is in phase II clinical trials for the treatment of rheumatoid arthritis and diabetic kidney disease. Baricitinib is shown below.
About Baricitinib
Baricitinib is a once-daily, oral, selective JAK1 and JAK2 inhibitor. There are four known JAK enzymes: JAK1, JAK2, JAK3 and TYK2. JAK-dependent cytokines have been implicated in the pathogenesis of a number of inflammatory and autoimmune diseases, suggesting that JAK inhibitors may be useful for the treatment of a broad range of inflammatory conditions. Baricitinib demonstrates approximately 100-fold greater potency of inhibition against JAK1 and JAK2 than JAK 3 in kinase assays.
In December 2009, Lilly and Incyte announced an exclusive worldwide license and collaboration agreement for the development and commercialization of baricitinib and certain follow-on compounds for patients with inflammatory and autoimmune diseases. Baricitinib is currently in Phase 3 clinical development for rheumatoid arthritis and Phase 2 development for psoriasis and diabetic nephropathy.
About Rheumatoid Arthritis
Rheumatoid arthritis is an autoimmune diseasei characterized by inflammation and progressive destruction of joints.ii More than 23 million people worldwide suffer from RA.iii Approximately three times as many women as men have the disease. Patients and physicians indicate there remains an important opportunity to improve patient care. Current treatment of RA includes the use of non-steroidal anti-inflammatory drugs, oral disease-modifying anti-rheumatic drugs such as methotrexate, and injectable biological response modifiers that target selected mediators implicated in the pathogenesis of RA.iv
About Baricitinib Phase 3 Trials
Lilly and Incyte have conducted four pivotal Phase 3 clinical trials of baricitinib in patients with moderately-to-severely active rheumatoid arthritis to support regulatory submission in most countries. An additional Phase 3 study was initiated to support clinical development in China and remains ongoing. The clinical trial program includes a wide range of patients including those who are methotrexate naïve, inadequate responders to methotrexate, inadequate responders to conventional disease-modifying anti-rheumatic drugs, or inadequate responders to TNF inhibitors. Patients completing any of the five Phase 3 studies can enroll in a long-term extension study. For additional information on this clinical trial program, please visit http://www.clinicaltrials.gov.
About Incyte
Incyte Corporation is a Wilmington, Delaware-based biopharmaceutical company focused on the discovery, development and commercialization of proprietary therapeutics for oncology and inflammation. For additional information on Incyte, please visit the Company’s web site athttp://www.incyte.com.
About Eli Lilly and Company
Lilly is a global healthcare leader that unites caring with discovery to make life better for people around the world. We were founded more than a century ago by a man committed to creating high-quality medicines that meet real needs, and today we remain true to that mission in all our work. Across the globe, Lilly employees work to discover and bring life-changing medicines to those who need them, improve the understanding and management of disease, and give back to communities through philanthropy and volunteerism. To learn more about Lilly, please visit us at http://www.lilly.com and newsroom.lilly.com/social-channels.
SOURCE: Eli Lilly
Biological Activity
Baricitinib (formerly INCB28050, LY3009104) is a selective orally bioavailable JAK1/JAK2 inhibitor. Baricitinib preferentially inhibits JAK1 and JAK2, with 10-fold selectivity over Tyk2 and 100-fold over JAK3. INCB-28050 (baricitinib) inhibits intracellular signaling of multiple proinflammatory cytokines including IL-6 at concentrations <50 nM. Baricitinib also inhibits pSTAT3 stimulated by IL-23 with IC50 of 20 nM in isolated naive T-cells. Baricitinib (INCB028050) was also effective in multiple murine models of arthritis, with no evidence of suppression of humoral immunity or adverse hematologic effects. Baricitinib reduces levels of pSTAT3 in a dose- and time-dependent manner in the peripheral blood of rAIA animals. INCB28050 (Baricitinib) (10 mg/mL, p.o.) improves a composite score of joint damage by 47% in the murine CIA model.
Conversion of different model animals based on BSA (Value based on data from FDA Draft Guidelines)
SpeciesMouseRatRabbitGuinea pigHamsterDog
Weight (kg)0.020.151.80.40.0810
Body Surface Area (m2)0.0070.0250.150.050.020.5
Km factor36128520
Animal A (mg/kg) = Animal B (mg/kg) multiplied byAnimal B Km
Animal A Km
For example, to modify the dose of resveratrol used for a mouse (22.4 mg/kg) to a dose based on the BSA for a rat, multiply 22.4 mg/kg by the Km factor for a mouse and then divide by the Km factor for a rat. This calculation results in a rat equivalent dose for resveratrol of 11.2 mg/kg.

str1
str2
As shown in Scheme 1, Rodgers et al. have reported the first synthetic route to baricitinib.
ref J.D. Rodgers, S. Shepard, T.P. Maduskuie, H. Wang, N. Falahatpisheh, M. Rafalski, A.G. Arvanitis, L. Sorace, R.K. Jalluri, J.S. Fridman and K. Vaddi, 2007, US20070135461.
tert-Butyl 3-oxoazetidine- 1-carboxylate (1) was employed as the starting material. This was transformed to compound 2 by a Horner–Emmons reaction, followed by deprotection of the N-Boc group in acidic conditions. The intermediate 4 was obtained by the sulfonamidation reaction of compound 3 with ethanesulfonyl chloride. The other part of baricitinib was acquired by utilising 4-chloro-7H-pyrrolo[2,3-d]pyrimidine (5) as the starting material. Compound 5 reacted with [2-(chloromethoxy)ethyl] trimethylsilane (SEM-Cl) to afford the intermediate 6, which was converted by reaction with 7 via the intermediate 8 to 4-(1H-pyrazol-4-yl)-7-{[2-(trimethylsilyl)ethoxy]methyl}-7Hpyrrolo[2,3-d]pyrimidine (9) via a Suzuki coupling reaction and a hydrolysis reaction. After the nucleophilic addition reaction and deprotection of the SEM group, baricitinib was obtained through eight steps. This synthetic route had drawbacks of high cost, low overall yield and the requirement of strict operating conditions.

PATENT

WO2009114512

EXAMPLES
Example 1. {l-(ethylsulfonyl)-3-[4-(7H-pyrrolo[2,3-d]pyrimidin-4-yl)-lH-pyrazol-l- yl]azetidin-3-yl}acetonitrile trifluoroacetic acid salt
Figure imgf000060_0001

Step 1. tert-butyl 3-(cyanomethylene)azetidine-l-carboxylate

0I \t
Figure imgf000061_0001
To a suspension of sodium hydride (60% dispersion in mineral oil, 0.257 g, 6.42 mmol) in tetrahydrofuran (32 mL) at 0 0C under a nitrogen atmosphere was added diethyl cyanomethylphosphonate (1.19 g, 6.72 mmol) (purchased from Aldrich). The reaction was then stirred for 45 minutes at room temperature. A solution of tert-butyl 3-oxoazetidine-l- carboxylate (1.00 g, 5.84 mmol) (purchased from Alfa Aesar) in tetrahydrofuran (8.8 mL) was introduced dropwise and the mixture was stirred for 16 hours. Brine and ethyl acetate were added and the layers separated. The aqueous layer was extracted with three portions of ethyl acetate. The combined extracts were dried over sodium sulfate, filtered and concentrated to afford product, used without further purification in Step 2 (1.12 g, 99%). 1H NMR (300 MHz, CDCl3): δ 5.38 (p, IH), 4.73-4.68 (m, 2H), 4.64-4.59 (m, 2H), 1.46 (s, 9H).
Step 2. tert-butyl 3-(cyanomethyl)’3-[4-(7-[2-(trimethylsilyl)ethoxy]methyl-7H-pyrrolo[2,3- djpyrim idin-4-yl) – 1 H-pyrazol-1 -yl]azetidine-l -carboxylate
Figure imgf000061_0002
To a solution of 4-(lH-pyrazol-4-yl)-7-[2-(trimethylsilyl)ethoxy]methyl-7H- pyrrolo[2,3-d]pyrimidine (4.61 g, 14.6 mmol) (prepared according to the method of WO 2007/070514 in Example 65, Step 2) and tert-butyl 3-(cyanomethylene)azetidine-l- carboxylate (2.84 g, 14.6 mmol) in acetonitrile (100 mL) was added 1,8- diazabicyclo[5.4.0]undec-7-ene (2.19 mL, 14.6 mmol). The reaction was stirred at room temperature for 16 hours. The acetonitrile was removed in vacuo and the residue was dissolved in ethyl acetate. This solution was sequentially washed with IN HCl and brine, dried over sodium sulfate, filtered and concentrated. The residue was purified by flash column chromatography, eluting with 80% ethyl acetate/hexanes to afford desired product (5.36 g, 72%).
1H NMR (300 MHz, CDCl3): δ 8.86 (s, IH), 8.44 (s, IH), 8.34 (s, IH), 7.42 (d, IH), 6.80 (d, IH), 5.68 (s, 2H), 4.54 (d, 2H), 4.29 (d, 2H), 3.59-3.51 (m, 2H), 3.33 (s, 2H), 1.47 (s, 9H), 0.96-0.89 (m, 2H), -0.06 (s, 9H); LCMS (M+H)+: 510.2.
Step 3. 3-[4-(7-[2-(trimethylsilyl)ethoxy]methyl-7H-pyrrolo[2,3-d]pyrimidin-4-yl)-lH- pyrazol- 1 -yl] azetidin-3-ylacetonitrile
Figure imgf000062_0001
To a solution of tert-butyl 3-(cyanomethyl)-3-[4-(7-[2-(trimethylsilyl)ethoxy]methyl- 7H-pyrrolo[2,3-d]pyrimidin-4-yl)-lH-pyrazol-l-yl]azetidine-l-carboxylate (5.36 g, 10.5 mmol) in 1,4-dioxane (100 mL) was added 4.00 M of hydrogen chloride in 1,4-dioxane (40 mL, 160 mmol) and the mixture was stirred at room temperature for 16 hours. The reaction was poured into saturated sodium bicarbonate solution sufficient to neutralize. The product was extracted with three portions of ethyl acetate. The combined extracts were washed with brine, dried over sodium sulfate, filtered and concentrated to afford product which was used without further purification (3.0 g, 69%). 1H NMR (400 MHz, CDCl3): δ 8.85 (s, IH), 8.42 (s, IH), 8.32 (s, IH), 7.41 (d, IH), 6.80 (d, IH), 5.68 (s, 2H), 4.30 (d, 2H), 3.88 (d, 2H), 3.58-3.51 (m, 2H), 3.42 (s, 2H), 0.96-0.89 (m, 2H), -0.06 (s, 9H); LCMS (M+H)+: 410.2. Step 4. l-(ethylsulfonyl)-3-[4-(7-[2-(trimethylsilyl)ethoxy]methyl-7H-pyrrolo[2,3- d]pyritnidin-4-yl)-lH-pyrazol-l-yl]azetidin-3-ylacetonitrile
Figure imgf000063_0001
To a solution of 3-[4-(7-[2-(trimethylsilyl)ethoxy]methyl-7H-pyrrolo[2,3- d]pyrimidin-4-yl)-lH-pyrazol-l-yl]azetidin-3-ylacetonitrile (0.100 g, 0.244 mmol) in tetrahydrofuran (2 mL) containing N,N-diisopropylethylamine (0.085 mL, 0.49 mmol) was added ethanesulfonyl chloride (0.023 mL, 0.24 mmol). After stirring for 1.5 hours, the reaction mixture was poured into dilute HCl and extracted with three portions of ethyl acetate. The combined extracts were washed with brine, dried over sodium sulfate, decanted and concentrated to afford product, used without further purification in Step 5 (111 mg, 91%).
1H NMR (300 MHz, CDCl3): δ 8.86 (s, IH), 8.63 (s, IH), 8.35 (s, IH), 7.45 (d, IH), 6.83 (d, IH), 5.68 (s, 2H), 4.63 (d, 2H), 4.26 (d, 2H), 3.54 (t, 2H), 3.42 (s, 2H), 3.09 (q, 2H), 1.41 (t, 3H), 0.92 (t, 2H), -0.06 (s, 9H); LCMS (M+H)+: 502.1.
Step 5. l-(ethylsulfonyl)-3-[4-(7H-pyrrolo[2,3-d]pyrimidin-4-yl)-lH-pyrazol-l-yl]azetidin-3- ylacetonitrile trifluoroacetate salt
To a solution of l-(ethylsulfonyl)-3-[4-(7-[2-(trimethylsilyl)ethoxy]methyl-7H- pyrrolo[2,3-d]pyrimidin-4-yl)-lH-pyrazol-l-yl]azetidin-3-ylacetonitrile (0.111 g, 0.22 mmol) in methylene chloride (3 mL) was added trifluoroacetic acid (2 mL) and the solution was stirred for 1.5 hours. The solvents were removed in vacuo and the residue was dissolved in methanol (3 mL) and ethylenediamine (0.1 mL) was added. After stirring for 3 hours, the volume was reduced in vacuo and the product was purified by preparative-HPLC/MS, (SunFire Cl 8 column, eluting with a gradient Of MeCNZH2O containing 0.1% TFA) to afford the product as the trifluoroacetic acid salt (50 mg, 47%). 1H NMR (400 MHz, d6-dmso): δ 12.55 (br d, IH), 9.03 (s, IH), 8.83 (s, IH), 8.56 (s, IH), 7.79-7.75 (m, IH), 7.24-7.19 (m, IH), 4.59 (d, 2H), 4.26 (d, 2H), 3.71 (s, 2H), 3.25 (q, 2H), 1.24 (t, 3H); LCMS (M+H)+: 372.1.
Alternatively, the deprotection and sulfonylation steps could be performed in the reverse order, as in Example 2.
Example 66. tert-Butyl 3-oxoazetidine-l-carboxylate (7).
A solution of tert-buty\ 3-hydroxyazetidine-l-carboxylate (24, 50 g, 289 mmol) in ethyl acetate (400 mL) was cooled to 0 0C. The resulting solution was then treated with solid TEMPO (0.5 g, 3.2 mmol, 0.011 equiv) and a solution of potassium bromide (KBr, 3.9 g, 33.2 mmol, 0.115 equiv) in water (60 mL) at 0 – 5 0C. While keeping the reaction temperature between 0 – 5 0C a solution of saturated aqueous sodium bicarbonate (NaHCO3, 450 mL) and an aqueous sodium hypochlorite solution (NaClO, 10 – 13 % available chlorine, 450 mL) were added. Once the solution of sodium hypochlorite was added, the color of the reaction mixture was changed immediately. When additional amount of sodium hypochlorite solution was added, the color of the reaction mixture was gradually faded. When TLC showed that all of the starting material was consumed, the color of the reaction mixture was no longer changed. The reaction mixture was then diluted with ethyl acetate (EtOAc, 500 mL) and two layers were separated. The organic layer was washed with water (500 rnL) and the saturated aqueous sodium chloride solution (500 mL) and dried over sodium sulfate (Na2SO4). The solvent was then removed under reduced pressure to give the crude product, tert-butyl 3-oxoazetidine-l-carboxylate (7, 48 g, 49.47 g theoretical, 97% yield), which was found to be sufficiently pure and was used directly in the subsequent reaction without further purification. For crude 7: 1H NMR (CDCl3, 300 MHz), δ 4.65 (s, 4H), 1.42 (s, 9H) ppm.
Example 67. tert-Buty\ 3-(cyanomethylene)azetidine-l-carboxylate (9). Diethyl cyanomethyl phosphonate (8, 745 g, 4.20 mol, 1.20 equiv) and anhydrous tetrahydrofuran (THF, 9 L) was added to a four-neck flask equipped with a thermowell, an addition funnel and the nitrogen protection tube at room temperature. The solution was cooled with an ice-methanol bath to -14 0C and a 1.0 M solution of potassium tert-butoxide (^-BuOK) in anhydrous tetrahydrofuran (THF, 3.85 L, 3.85 mol, 1.1 equiv) was added over 20 min while keeping the reaction temperature below -5 0C. The resulting reaction mixture was stirred for 3 h at -10 0C and a solution of l-terf-butoxycarbonyl-3-azetidinone (7, 600 g, 3.50 mol) in anhydrous tetrahydrofuran (THF, 2 L) was added over 2 h while keeping the internal temperature below -5 0C. The reaction mixture was stirred at -5 to -10 0C over 1 h and then slowly warmed up to room temperature and stirred at room temperature for overnight. The reaction mixture was then diluted with water (4.5 L) and saturated aqueous sodium chloride solution (NaCl, 4.5 L) and extracted with ethyl acetate (EtOAc, 2 x 9 L). The combined organic layers were washed with brine (6 L) and dried over anhydrous sodium sulfate (Na2SO4). The organic solvent was removed under reduced pressure and the residue was diluted with dichloromethane (CH2Cl2, 4 L) before being absorbed onto silica gel (Siθ2, 1.5 Kg). The crude product, which was absorbed on silica gel, was purified by flash column chromatography (SiO2, 3.5 Kg, 0 – 25% EtOAc/hexanes gradient elution) to afford tert-butyl 3-(cyanomethylene)azetidine-l-carboxylate (9, 414.7 g, 679.8 g theoretical, 61% yield) as white solid. For 9: 1H NMR (CDCl3, 300MHz), δ 5.40 (m, IH), 4.70 (m, 2H), 4.61 (m, 2H), 1.46 (s, 9H) ppm; Ci0H14N2O2 (MW, 194.23), LCMS (EI) mle 217 (M+ + Na).
Figure imgf000133_0001
C8H13NO3 MoI Wt 171 19
Figure imgf000133_0002
2
Figure imgf000133_0003
11 step 3 10
C7H10N2O2S C5H7CIN2 MoI Wt 186 23 MoI Wt 130 58
Example 68. 2-(l-(Ethylsulfonyl)azetidin-3-ylidene)acetonitrile (11).
A solution of tert-buty\ 3-(cyanomethylene)azetidine-l-carboxylate (9, 100Og, 5.2 mol) in acetonitrile (7 L) and a 3 N aqueous HCl solution (7 L) was stirred at room temperature for 18 h. When HPLC showed that all the starting material (9) was consumed, the reaction mixture was concentrated under reduced pressure to dryness. The residue, which contains the crude desired deprotection product (10), was then suspended in acetonitrile (12 L) and the resulting suspension was cooled to O – 5 0C. Diisopropyethylamine (DIEA, 3.14 L, 18.03 mol, 3.5 equiv) was then slowly added while keeping the internal temperature below 5 0C. The resulting homogeneous solution was allowed to cool down to O 0C and ethane sulfonyl chloride (EtSO2Cl, 730 mL, 7.73 mol, 1.5 equiv) was added over 1 h while keeping the internal temperature below 5 0C. The resulting reaction mixture was allowed to gradually warm to room temperature and stirred at room temperature for overnight. When HPLC showed that the reaction was complete, the reaction mixture was concentrated under reduced pressure to a volume of approximately 2 L. The bath temperature of the rotary evaporator is set to not exceed 45 0C. The concentrated residue was then diluted with dichloromethane (CH2CI2, 10 L) and the resulting dichloromethane solution was washed with aqueous sodium chloride solution (10 L). The aqueous phase was back extracted with dichloromethane (CH2CI2, 5 L). The combined organic layers were dried over anhydrous sodium sulfate
(Na2SO^ and the residue was absorbed onto silica gel (SiO2, 1 Kg) under reduced pressure. The bath temperature of the rotary evaporator was set to not exceed 45 0C. The material was then loaded onto a silica gel column (SiO2, 2.5 Kg) and eluted with 20 – 60 % ethyl acetate in heptane to afford 2-(l-(ethylsulfonyl)azetidin-3-ylidene)acetonitrile (11, 882 g, 968.4 g theoretical, 91 % yield) as off-white solids. For 11: 1H NMR (CDCl3, 300 MHz) δ 5.46 (m, IH), 4.77 (m, 2H), 4.70 (m, 2H), 3.05 (q, 2H), 1.39 (t, 3H) ppm; C7Hi0N2O2S (MW, 186.23), LCMS (EI) mle 187 (M+ + H).
Example 69. 2-(l-(Ethylsulfonyl)-3-(4-(7-((2-(trimethyIsiIyl)ethoxy)methyl)-7H- pyrrolo[2,3-</]pyrimidin-4-yl)-lH-pyrazol-l-yl)azetidin-3-yl)acetonitrile (12).
Method A. To a suspension of 4-(lH-pyrazol-4-yl)-7-((2-
(trimethylsilyl)ethoxy)methyl)-7H-pyrrolo[2,3-^pyrimidine (5, 440 g, 1.395 mol) and 2-(l- (ethylsulfonyl)azetidin-3-ylidene)acetonitrile (11, 312.4 g, 1.68 mol, 1.2 equiv) in acetonitrile (4.4 L) was added DBU (249.8 mL, 1.67 mol, 1.2 equiv) drop wise to keep the reaction temperature between 15 – 25 0C. After adding DBU, the reaction mixture became homogeneous, but a precipitate appeared in 30 min. The reaction mixture was stirred for 3 h at room temperature. When ΗPLC showed that the reaction was deemed complete, the reaction mixture was quenched with water (11 L). The resulting mixture was stirred at room temperature for additional 30 min and then filtered. The solid cake was washed with water (4 L), MTBE (2 L) and dried in vacuum oven at 35 0C for 24 h to afford crude 2-(l –
(ethylsulfonyl)-3-(4-(7-((2-(trimethylsilyl)ethoxy)methyl)-7H-pyrrolo[2,3-(i]pyrimidin-4-yl)- lH-pyrazol-l-yl)azetidin-3-yl)acetonitrile (12, 681 g, 699.8 g theoretical, 97.3 % yield) as white solids, which was found to be sufficiently pure for the subsequent reaction without further purification. For 12: 1HNMR (CDCl3, 300 MHz), δ 8.86 (s, IH), 8.45 (s, IH), 8.35 (s, IH), 7.43 (d, IH), 6.80 (d, IH), 5.68 (s, 2H), 4.65 (d, 2H), 4.27 (d, 2H), 3.55 (s, 2H), 3.4 (t, 2H), 3.07 (m, 2H), 1.42 (m, 3H), 0.92 (m, 2H), -0.05 (s, 9H) ppm; C22H3IN7O3SSi (MW, 501.68), LCMS (EI) mle 502 (M+ + H).
Figure imgf000135_0001
12
C15H21N5OSi C22H31N7O3SSi MoI Wt 315 45 MoI Wt 501 68
Figure imgf000135_0002
Phosphate salt
C16H17N7O2S C16H20N7O6PS
MoI Wt 371 42 MoI Wt 469 41
Example 72. tert-Butyl 3-(cyanomethyl)-3-(4-(7-((2-(trimethylsilyl)ethoxy)methyl)-7H- pyrroIo[2,3-rf]pyrimidin-4-yl)-lH-pyrazol-l-yl)azetidine-l-carboxyIate (15).
To a suspension of tert-butyl 3-(cyanomethylene)azetidine-l-carboxylate (9, 417.2 g, 2.15 mol, 1.05 equiv) and 4-(lH-pyrazol-4-yl)-7-((2-(trimethylsilyl)ethoxy)methyl)-7H- pyrrolo[2,3-<f]pyrimidine (5, 645 g, 2.04 mol) in acetonitrile (4.9 L) was added DBU (30.5 mL, 0.204 mol, 0.1 equiv) drop wise at room temperature. The resulting reaction mixture was then stirred at room temperature for 3 h. After about 1 h, a clear, brown solution was obtained. When LCMS showed that no starting material remained, silica gel (SiO2, 1 Kg) was added and the mixture was concentrated to dryness under reduced pressure. This material, which contains the crude desired product (15), was then loaded onto a pre-packed silica column (Siθ2, 2.5 Kg) and the column was eluted with 60 – 80% of ethyl acetate/heptane. The fractions containing the pure desired product (15) were combined and concentrated under reduced pressure to give the desired product as thick oil which was then stirred in heptane at room temperature until crystallization occurred. The solids were collected by filtration and washed with heptane to afford tert-buty\ 3-(cyanomethyl)-3-(4-(7-((2- (trimethylsilyl)ethoxy)methyl)-7H-pyrrolo[2,3-ύ(]pyrimidin-4-yl)-lH-pyrazol-l-yl)azetidine- 1-carboxylate (15, 1014.9 g, 1039.7 g theoretical, 97.6% yield) as white solids. For 15: 1H NMR (DMSO-^6, 300 MHz) δ 8.93 (s, IH), 8.77 (s, IH), 8.47 (s, IH), 7.80 (d, IH, J= 3.8 Hz), 7.20 (d, IH, J = 3.7 Hz), 5.63 (s, 2H), 4.50 (d, 2H, J= 9.3 Hz), 4.21 (d, 2H, J= 9.3 Hz), 3.66 (s, 2H), 3.52 (t, 2H, J= 7.8 Hz), 1.40 (s, 9H), 0.82 (t, 2H, J= 8.1 Hz), -0.12 (s, 9H) ppm; C25H35N7O3Si (MW, 509.68), LCMS (EI) m/e 510 (M+ + H) and 532 (M+ + Na).
Figure imgf000138_0001
15
C15H21N5OSi C25H35N7O3Si MoI Wt 31545 MoI Wt 509 68
Figure imgf000138_0002
16 12
C20H27N7OSi C22H31N7O3SSi MoI Wt 409 56 MoI Wt 501 68
Figure imgf000138_0003
14 phosphate
C16H17N7O2S C16H20N7O6PS
Figure imgf000138_0004
MoI Wt 371 42 MoI Wt 46941
Example 77. (4-(l-(3-(Cyanomethyl)-l-(ethylsulfonyl)azetidin-3-yl)-lH-pyrazol-4-yl)- 7H-pyrrolo[2,3-</]pyrimidin-7-yl)methyl pivalate (20).
To a suspension of [4-(lH-pyrazol-4-yl)-7H-pyrrolo[2,3-</|pyrimidin-7-yl]methyl pivalate (19, 10.0 g, 33.4 mmol) and 2-(l-(ethylsulfonyl)azetidin-3-ylidene)acetonitrile (11, 6.22 g, 33.4 mmol, 1.0 equiv) in N,N-dimethylformamide (DMF, 20 mL) was added DBU (254 mg, 1.67 mmol, 0.05 equiv) drop wise to keep the reaction temperature between 15 – 25 0C. After adding DBU, the reaction mixture became homogeneous within 90 min. The reaction mixture was stirred for 3 h at room temperature. When ΗPLC showed that the reaction was deemed complete, the reaction mixture was quenched with water (120 mL) and acetonitrile (80 mL). The resulting mixture was stirred at room temperature for an additional 30 min. The solids were collected by filtration, washed with a mixture of acetonitrile and water (2/3 by volume, 2 x 20 mL), and dried in vacuum oven at 40 – 45 0C for 24 h to afford crude (4-(l-(3-(cyanomethyl)-l-(ethylsulfonyl)azetidin-3-yl)-lH-pyrazol-4-yl)-7H- pyrrolo[2,3-</)pyrimidin-7-yl)methyl pivalate (20, 14.5 g, 16.2 g theoretical, 89.5 % yield) as white solids, which was found to be sufficiently pure (> 98.0% by ΗPLC) for the subsequent reaction without further purification. For 20: 1FTNMR (CDCl3, 300 MHz), δ 8.87 (s, IH), 8.43 (s, IH), 8.37 (s, IH), 7.51 (d, IH, J= 3.6 Hz), 6.76 (d, IH, J= 3.6 Hz), 6.26 (s, 2H),
4.64 (d, 2H, J = 9.6 Hz), 4.25 (d, 2H, J = 9.6 Hz), 3.41 (s, 2H), 3.09 (q, 2H, J= 7.6 Hz), 1.42 (t, 3H, J= 7.6 Hz), 1.17 (s, 9H) ppm; C22H27N7O4S (MW, 485.56), LCMS (EI) mle 486 (M+ + H).
Figure imgf000143_0001
C15H17N5O2 C22H27N7O4S MoI Wl 299 33 MoI Wt 48556
Figure imgf000143_0002
14 phosphate
C16H17N7O2S C16H20N7O6PS MoI Wt 371 42 MoI Wt 46941

str1

 

PAPER

A highly efficient method for the synthesis of baricitinib was developed. The starting material tert-butyl 3-oxoazetidine-1-carboxylate was converted to intermediate 2-(1-(ethylsulfonyl)azetidin-3-ylidene)acetonitrile via the Horner–Emmons reaction, deprotection of the N-Boc-group and a final sulfonamidation reaction. Then the nucleophilic addition reaction was carried out smoothly to afford the borate intermediate in the presence of 1,8-diazabicyclo[5.4.0]undec-7-ene under reflux. Finally, the desired compound baricitinib was obtained by the Suzuki coupling reaction of 4-chloro-7-H-pyrrolo[2,3-d]pyrimidine with the above borate intermediate. All compounds were characterised by IR, MS, 1H NMR and 13C NMR. The overall yield in this synthetic route was as high as 49%. Moreover, this procedure is straightforward to carry out, has low cost and is suitable for industrial production.

str1

In order to improve the procedure, we designed a novel synthetic route for the synthesis of baricitinib (Scheme 2). Similarly, we also applied tert-butyl 3-oxoazetidine-1-carboxylate (1) as the starting material. First, we optimised the preparation of compound 4. In the Horner–Emmons reaction, NaH was used as the base instead of t-BuOK, which led to a yield as high as 84%. Then the deprotection of the N-Boc group was carried out smoothly under trifluoroacetic acid (TFA) cleavage conditions to afford compound 3, which was reacted with ethanesulfonyl chloride without further purification. Next, the nucleophilic addition reaction between compound 4 and 4-(4,4,5,5-tetramethyl-1,3,2- dioxaborolan-2-yl)-lH-pyrazole (11) proceeded successfully in the presence of 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU). With the intermediate compound 12 in hand, we optimised the conditions of the Suzuki coupling reaction with compound 5. Several coupling systems were evaluated, such as Pd(PPh3 )4 – K2 CO3 –t-butanol/H2 O, Pd(PPh3 )4 –Na2 CO3 –t-butanol/H2 O and Pd(OAc)2 –K2 CO3 –dioxane/H2 O. The Pd(PPh3 )4 –CsF–t-butanol/ toluene/H2 O system afforded the most satisfactory yield. Finally, baricitinib was obtained efficiently and the overall yield was as high as 49% based on tert-butyl 3-oxoazetidine-1-carboxylate (1)

PATENT

Baricitinib is a Janus kinase (JAK) inhibitor. It is chemically designated as { 1 (ethylsulfonyl)-3-[4-(7H-pyrrolo[2,3-d]pyrimidin-4-yl)-lH-pyrazol-l-yl]azetidin-3-yl}acetonitrile, having the structure as depicted in Formula I.
Formula I
U.S. Patent No. 8,158,616 discloses processes for the preparation of baricitinib of Formula I and [4-(lH-pyrazol-4-yl)-7H-pyrrolo[2,3-d]pyrimidin-7-yl]methyl pivalate of Formula II.
Formula II
U.S. Patent No. 8, 158,616 involves a three-step process for the preparation of [4- (lH-pyrazol-4-yl)-7H-pyrrolo[2,3-d]pyrimidin-7-yl]methyl pivalate of Formula II as depicted in Scheme 1 below:
Scheme 1
Formula V
Formula VI
Formula II Formula VII
The process disclosed in U.S. Patent No. 8, 158,616 involves the use of sodium hydride as a base for reacting 4-chloro-7H-pyrrolo[2,3-d]pyrimidine of Formula III with chloromethyl pivalate of Formula IV, and the use of a protected pyrazole borolane derivative of Formula VI for the conversion of (4-chloro-7H-pyrrolo[2,3-d]pyrimidin-7- yl)methyl 2,2-dimethylpropanoate of Formula V into [4-(lH-pyrazol-4-yl)-7H- pyrrolo[2,3-d]pyrimidin-7-yl]methyl pivalate of Formula II.
The use of sodium hydride is not suitable on an industrial scale due to its inflammable and hazardous nature. The use of a protected pyrazole borolane derivative of Formula VI increases the cost of the manufacturing process, as an additional deprotection step is required for obtaining [4-(lH-pyrazol-4-yl)-7H-pyrrolo[2,3-d]pyrimidin-7-yl]methyl pivalate of Formula II.
Thus, there exists a need for the development of an economical and industrially advantageous process for the preparation of [4-(lH-pyrazol-4-yl)-7H-pyrrolo[2,3-d]pyrimidin-7-yl]methyl pivalate of Formula II that avoids the use of sodium hydride and involves a lesser number of steps.
The present invention provides a convenient, economical, and industrially advantageous two-step process for the preparation of [4-(lH-pyrazol-4-yl)-7H-pyrrolo[2,3-d]pyrimidin-7-yl]methyl pivalate of Formula II. The process of the present invention involves the use of an alkali or alkaline earth metal hydroxide, carbonate, or bicarbonate as a base for reacting 4-chloro-7H-pyrrolo[2,3-d]pyrimidine of Formula III with chloromethyl pivalate of Formula IV, and the use of an unprotected pyrazole borolane of Formula VIII for the conversion of (4-chloro-7H-pyrrolo[2,3-d]pyrimidin-7-yl)methyl 2,2-dimethylpropanoate of Formula V into [4-(lH-pyrazol-4-yl)-7H-pyrrolo[2,3-d]pyrimidin-7-yl]methyl pivalate of Formula II. The process of the present invention provides [4-(lH-pyrazol-4-yl)-7H-pyrrolo[2,3-d]pyrimidin-7-yl]methyl pivalate of Formula II in high yield.
A first aspect of the present invention provides a process for the preparation of [4-(lH-pyrazol-4-yl)-7H-pyrrolo[2,3-d]pyrimidin-7-yl]methyl pivalate of Formula II,
Formula II
comprising the steps of:
i) reacting 4-chloro-7H-pyrrolo[2,3-d]pyrimidine of Formula III
Formula III
with chloromethyl pivalate of Formula IV
Formula IV
in the presence of an alkali or alkaline earth metal hydroxide, carbonate, bicarbonate as a base to obtain (4-chloro-7H-pyrrolo[2,3-d]pyrimidin-7- yl)methyl 2,2-dimethylpropanoate of Formula V; and
ii) reacting the (4-chloro-7H-pyrrolo[2,3-d]pyrimidin-7-yl)methyl 2,2- dimethylpropanoate of Formula V with 4-(4,4,5,5-tetramethyl-l,3,2 dioxaborolan-2-yl)-lH-pyrazole of Formula VIII
Formula VIII
to obtain the [4-(lH-pyrazol-4-yl)-7H-pyrrolo[2,3-d]pyrimidin-7-yl]methyl pivalate of Formula II.
A second aspect of the present invention provides a process for the preparation of baricitinib of Formula I,
Formula I
comprising the steps of:
i) reacting 4-chloro-7H-pyrrolo[2,3-d]pyrimidine of Formula III
Formula III
with chloromethyl pivalate of Formula IV
Formula IV
in the presence of an alkali or alkaline earth metal hydroxide, carbonate, or bicarbonate base to obtain (4-chloro-7H-pyrrolo[2,3-d]pyrimidin-7-yl)methyl 2,2-dimethylpropanoate of Formula V;
Formula V
ii) reacting the (4-chloro-7H-pyrrolo[2,3-d]pyrimidin-7-yl)methyl 2,2- dimethylpropanoate of Formula V with 4-(4,4,5,5-tetramethyl-l,3,2- dioxaborolan-2-yl)-lH-pyrazole of Formula VIII
Formula VIII
to obtain [4-( lH-pyrazol-4-yl)-7H-pyrrolo[2,3-d]pyrimidin-7-yl]methyl pivalate of Formula II; and
Formula II
iii) reacting the [4-(lH-pyrazol-4-yl)-7H-pyrrolo[2,3-d]pyrimidin-7-yl]methyl pivalate of Formula II with [l-(ethylsulfonyl)azetidin-3-ylidene]acetonitrile of Formula IX
Formula IX
to obtain baricitinib of Formula I.
EXAMPLES
Example 1 : Preparation of (4-chloro-7H-pyrrolor2.3-dlpyrimidin-7-yl)methyl 2.2-dimethylpropanoate (Formula V)
4-Chloro-7H-pyrrolo[2,3-d]pyrimidine (25 g; Formula III), potassium carbonate (27 g), and chloromethyl pivalate (27 g; Formula IV) were added to a reaction vessel containing N,N-dimethylformamide (100 mL) at ambient temperature. The reaction mixture was stirred for 14 hours. The progress of the reaction was monitored by thin layer chromatography. Water (250 mL) was added to the reaction mixture, and then the mixture was stirred for 2 hours. The reaction mixture was filtered, then washed with water (50 mL), and then dried under reduced pressure at 40°C to 45°C for 12 hours to obtain (4-chloro-7H-pyrrolo[2,3-d]pyrimidin-7-yl)methyl 2,2-dimethylpropanoate.
Yield: 98.85%
Example 2: Preparation of r4-(lH-pyrazol-4-yl)-7H-pyrrolor2.3-dlpyrimidin-7-yllmethyl pivalate (Formula II)
(4-Chloro-7H-pyrrolo[2,3-d]pyrimidin-7-yl)methyl 2,2-dimethylpropanoate (10 g; Formula V), water (50 mL), and potassium carbonate (15.5 g) were added into a reaction vessel at ambient temperature. 4-(4,4,5,5-Tetramethyl-l,3,2-dioxaborolan-2-yl)-lH-pyrazole (8.7 g; Formula VIII), 1,4-dioxane (100 mL), and
tetrakis(triphenylphosphine)palladium(0) (0.08 g) were added to the reaction mixture. The reaction mixture was heated to a temperature of 80°C to 85°C, and then stirred at the same temperature for 14 hours. The progress of the reaction was monitored by thin layer chromatography. On completion, ethyl acetate (100 mL) was added to the reaction mixture. The contents were stirred for 1 hour, then filtered through a Hyflo®, and then washed with ethyl acetate (40 mL). The organic layer was separated, and then concentrated under reduced pressure to obtain [4-(lH-pyrazol-4-yl)-7H-pyrrolo[2,3-d]pyrimidin-7-yl]methyl pivalate.
Yield: 82.27%
PATENT
WO-2014194195
PATENT
PATENT
The present invention provides processes for the preparation of baricitinib of Formula I and an intermediate of Formula V. The present invention also provides the of the intermediate of Formula V for the preparation of baricitinib.
 
Formula V
Background of the Invention
Baricitinib is a Janus kinase (JAK) inhibitor. It is chemically designated as (ethylsulfonyl)-3-[4-(7H-pyrrolo[2,3-d]pyrimidin-4-yl)-lH-pyrazol-l-yl]azetidin-3 yl}acetonitrile, having the structure as depicted in Formula I.
 
Formula I
U.S. Patent No. 8,158,616 discloses a process for the preparation of baricitinib comprising the reaction of 2-(l-(ethylsulfonyl)azetidin-3-ylidene)acetonitrile of Formula II with 4-(lH-pyrazol-4-yl)-7H-pyrrolo[2,3-d]pyrimidin-7-yl methyl pivalate of Formula
III to provide an intermediate of Formula IV, followed by deprotection of the intermediate of Formula IV to obtain baricitinib of Formula I, as depicted in Scheme I below:
Scheme I
 
Formula IV
The process disclosed in U.S. Patent No. 8, 158,616 requires a deprotection step in the last stage of the synthesis, which adds to the cost of the overall synthesis.
Thus, there exists a need for an alternate, cost-effective, and industrially advantageous process for the preparation of baricitinib.
EXAMPLES
Example 1 : Preparation of 3-(cvanomethylene)azetidine hydrochloride (Formula VIP
Aqueous hydrochloric acid (6N, 10 mL) and montmorillonite K-10 (2 g) were added into a reaction vessel at ambient temperature. The contents were stirred for 1 hour, and then filtered under reduced pressure to obtain activated montmorillonite K-10. The activated montmorillonite K-10 was added into another reaction vessel containing tert-butyl 3-(cyanomethylidene)azetidine-l-carboxylate (2 g; Formula VI) and methanol (20
mL) at ambient temperature. The reaction mixture was refluxed for about 12 hours to about 15 hours. On completion, the reaction mixture was filtered under reduced pressure followed by recovery of methanol under reduced pressure at about 40°C to about 45°C to obtain 3-(cyanomethylene)azetidine hydrochloride.
Yield: 75%
Example 2: Preparation of 2-(l-(ethylsulfonyl)azetidin-3-ylidene)acetonitrile (Formula ID
N,N-Diisopropylethylamine (4.5 mL) was added into a reaction vessel containing acetonitrile (50 mL) and 3-(cyanomethylene)azetidine hydrochloride (1.5 g; Formula VII) at about 0°C to about 10°C. The reaction mixture was stirred for about 10 minutes.
Ethanesulfonyl chloride (2.22 g) was added into the reaction mixture at about 0°C to about 5°C over about 5 minutes. The temperature of the reaction mixture was raised to about 20°C to about 25 °C, and then the reaction mixture was stirred for about 16 hours. On completion of the reaction, acetonitrile was recovered from the reaction mixture under reduced pressure at about 40°C to about 45°C to obtain an oily residue. Dichloromethane (50 mL) was added into the residue. The contents were washed with a saturated sodium chloride solution (30 mL), followed by complete recovery of dichloromethane under reduced pressure at about 40°C to obtain 2-(l-(ethylsulfonyl)azetidin-3-ylidene)acetonitrile .
Yield: 98.59%
Example 3: Preparation of { l-(ethylsulfonyl)-3-[4-(4.4.5.5-tetramethyl-1.3.2-dioxaborolan-2-yl)-lH-pyrazol-l-yllazetidin-3-yl}acetonitrile (Formula V)
1,4-Dioxane (20 mL) was added into a reaction vessel containing a solution of potassium carbonate (4.5 g) in water (30 mL) at about 20°C to about 25 °C. 2-(l-(Ethylsulfonyl)azetidin-3-ylidene)acetonitrile (2 g; Formula II) and 4-(4,4,5,5-tetramethyl-l,3,2-dioxaborolan-2-yl)-lH-pyrazole (2.30 g; Formula VIII) were added into the reaction mixture at about 20°C to about 25 °C. The reaction mixture was stirred at about 20°C to about 25 °C for about 16 hours to about 18 hours. On completion of the reaction, 1,4-dioxane was recovered from the reaction mixture under reduced pressure at about 45 °C to obtain a residue. Ethyl acetate (20 mL) was added into the residue, and the contents were stirred for about 5 minutes. The organic and aqueous layers were separated. The organic layer was concentrated under reduced pressure at about 45 °C to obtain { l-(ethylsulfonyl)- 3-[4-(4,4,5,5-tetramethyl-l,3,2-dioxaborolan-2-yl)-lH-pyrazol-l-yl]azetidin-3-yl}acetonitrile.
Yield: 85.78%
Mass: 381.4 [M + H]+
Example 4: Preparation of baricitinib (Formula I)
4-Chloro-7H-pyrrolo[2,3-d]pyrimidine (0.8 g; Formula IX) was added into a reaction vessel containing a solution of potassium carbonate (2.1 g) in water (30 mL) at about 20°C to about 25°C. A solution of { l-(ethylsulfonyl)-3-[4-(4,4,5,5-tetramethyl-l,3,2-dioxaborolan-2-yl)-lH-pyrazol-l-yl]azetidin-3-yl}acetonitrile (2.0 g; Formula V) in 1,4-dioxane (30 mL) was added into the reaction mixture at about 20°C to about 25 °C, followed by the addition of tetrakis(triphenylphosphine)palladium(0) (0.1 g). The reaction mixture was stirred at about 80°C to about 85°C for about 5 hours. On completion of the reaction, 1,4-dioxane was recovered from the reaction mixture under reduced pressure at about 45°C to obtain a residue. Ethyl acetate (50 mL) was added into the residue, and then the contents were stirred for about 5 minutes. The organic and aqueous layers were separated. The organic layer was concentrated under reduced pressure at about 45°C to obtain baricitinib.
Yield: 99.0%

Patent

Figure 8 is a crystalline form II 1 the H NMR FIG.

PATENT

Figure 4: Infra-red (IR) spectrum of the crystalline form of baricitinib.
Example: Preparation of crystalline form of baricitinib
(4-( 1 -(3-(Cyanomethyl)- 1 -(ethylsulfonyl)azetidin-3-yl)- lH-pyrazol-4-yl)-7H-pyrrolo [2,3-d]pyrimidin-7-yl)methyl pivalate (8 g), methanol (40 mL), tetrahydrofuran (160 mL), and 1M sodium hydroxide (18.4 mL) were added into a reaction vessel at 20°C to 25°C. The reaction mixture was stirred for 3 hours. Progress of the reaction was monitored by thin layer chromatography. On completion, the reaction mixture was quenched with water (80 mL). The pH was adjusted to 7.0 to 7.5 by adding IN hydrochloric acid. Half of the solvent was recovered at a temperature of 40°C to 50°C. The reaction mixture was stirred at 20°C to 25°C for 18 hours, and then cooled to 5°C to 10°C. The solids were filtered, washed with a mixture of acetonitrile (50 mL) and water (100 mL), and then dried at 40°C to 50°C under reduced pressure for 24 hours to obtain the crystalline form of baricitinib.
Yield: 70%

PATENT


str1

Figure 1 : X-ray Powder Diffraction (XRPD) pattern of the crystalline form of baricitinib.
str2
Figure 2: Differential Scanning Calorimetry (DSC) thermogram of the crystalline form of baricitinib.
str3
Figure 3 : Thermogravimetric Analysis (TGA) of the crystalline form of baricitinib.
str4
Figure 4: Infra-red (IR) spectrum of the crystalline form of baricitinib.
The crystalline form of baricitinib is further characterized by a DSC having endotherms at about 180.63°C and about 207.98°C.
The crystalline form of baricitinib has a water content of about 3%, as determined by TGA.
The crystalline form of baricitinib is also characterized by an XRPD pattern as depicted in Figure 1, a DSC thermogram as depicted in Figure 2, a TGA as depicted in Figure 3, and an IR spectrum as depicted in Figure 4.
The preparation of the crystalline form of baricitinib is carried out by reacting (4-(l-(3-(cyanomethyl)-l-(ethylsulfonyl)azetidin-3-yl)-lH-pyrazol-4-yl)-7H-pyrrolo [2,3-d]pyrimidin-7-yl)methyl pivalate with a base in the presence of one or more solvents at a temperature of about 15°C to 50°C, stirring the reaction mixture for about 30 minutes to about 10 hours, partially recovering the solvent(s) from the reaction mixture at a temperature of about 35°C to about 60°C under reduced pressure, stirring the contents at about 15°C to 35°C for about 5 hours to about 24 hours, filtering the solid, washing the solid with a mixture of acetonitrile and water, and drying.
The (4-( 1 -(3 -(cyanomethyl)- 1 -(ethylsulfonyl)azetidin-3 -yl)- lH-pyrazol-4-yl)-7H-pyrrolo [2,3-d]pyrimidin-7-yl)methyl pivalate may be obtained by following the process disclosed in U.S. Patent No. 8, 158,616.



Example: Preparation of crystalline form of baricitinib
(4-( 1 -(3-(Cyanomethyl)- 1 -(ethylsulfonyl)azetidin-3-yl)- lH-pyrazol-4-yl)-7H-pyrrolo [2,3-d]pyrimidin-7-yl)methyl pivalate (8 g), methanol (40 mL), tetrahydrofuran (160 mL), and 1M sodium hydroxide (18.4 mL) were added into a reaction vessel at 20°C to 25°C. The reaction mixture was stirred for 3 hours. Progress of the reaction was monitored by thin layer chromatography. On completion, the reaction mixture was quenched with water (80 mL). The pH was adjusted to 7.0 to 7.5 by adding IN hydrochloric acid. Half of the solvent was recovered at a temperature of 40°C to 50°C. The reaction mixture was stirred at 20°C to 25°C for 18 hours, and then cooled to 5°C to 10°C. The solids were filtered, washed with a mixture of acetonitrile (50 mL) and water (100 mL), and then dried at 40°C to 50°C under reduced pressure for 24 hours to obtain the crystalline form of baricitinib.
Yield: 70%



PATENT

EXAMPLES
Comparative Examples
Example 1 : Repetition of the process according to Example 78. Method B of U.S. Patent No. 8.158.616
4-( 1 -(3 -(Cyanomethyl)- 1 -(ethylsulfonyl)azetidin-3 -yl)- lH-pyrazol-4-yl)-7H- pyrrolo[2,3-d]pyrimidin-7-yl)methyl pivalate (1 g), methanol (5 mL), tetrahydrofuran (20 mL), and 1M sodium hydroxide (2.3 mL) were added into a reaction vessel at 20°C to 25 °C. The reaction mixture was stirred for 3 hours. Progress of the reaction was monitored by thin layer chromatography. On completion, the reaction mixture was quenched by adding water (20 mL). The pH was adjusted to 7.0 to 7.5 by adding IN hydrochloric acid, and the contents were stirred for 1.5 hours. No solid material was obtained. Example 2: Repetition of the process according to Example 78. Method C of U.S. Patent No. 8.158.616
4-( 1 -(3 -(Cyanomethyl)- 1 -(ethylsulfonyl)azetidin-3 -yl)- lH-pyrazol-4-yl)-7H- pyrrolo[2,3-d]pyrimidin-7-yl)methyl pivalate (2 g), lithium hydroxide monohydrate (0.51 g), acetonitrile (8 mL), and 2-propanol (2 mL) were added into a reaction vessel at 20°C to 25°C. The reaction mixture was stirred at 45°C to 50°C for 6 hours. Progress of the reaction was monitored by thin layer chromatography. On completion, the reaction mixture was cooled to 20°C to 25°C. The pH was adjusted to 6.0 to 7.0 by adding IN hydrochloric acid, and the contents were stirred overnight. No solid material was obtained.
Working Example:
Preparation of an amorphous form of baricitinib
4-( 1 -(3 -(Cyanomethyl)- 1 -(ethylsulfonyl)azetidin-3 -yl)- lH-pyrazol-4-yl)-7H- pyrrolo[2,3-d]pyrimidin-7-yl)methyl pivalate (1 g), methanol (5 mL), tetrahydrofuran (20 mL), and 1M sodium hydroxide (2.3 mL) were added into a reaction vessel at 20°C to 25 °C. The reaction mixture was stirred for 3 hours. Progress of the reaction was monitored by thin layer chromatography. On completion, the reaction mixture was quenched by adding water (20 mL). The pH was adjusted to 7.0 to 7.5 by adding IN hydrochloric acid, followed by completely recovering the solvent under reduced pressure at 40°C to 50°C. A sticky material was obtained. Water (10 mL) was added to the sticky material at 20°C to 25°C. The contents were stirred for 10 minutes. A solid material was precipitated out. The solid material was filtered, washed with water (20 mL), and then dried under reduced pressure at 40°C to 45°C for 24 hours to obtain the amorphous form of baricitinib.
Yield: 81%.
The amorphous form of baricitinib may be used in a pharmaceutical composition with one or more pharmaceutically acceptable carriers, diluents, or excipients, and optionally other therapeutic ingredients. The pharmaceutical composition may be used for the treatment of JAK-associated diseases.

PATENT
CN 105693731

Baricitinib crystal form A and preparation method

A process for prepn. of Baricitinib crystal form A is disclosed.  The process comprises recrystn. of Baricitinib with DMF and water or alc., or ether to get the white powder Baricitinib crystal form A.  The obtained crystal form A has high high-​temp. stability, high-​humidity stability, and light stability with XRPD spectrum at 2θ (±> 0.2) of 12.46, 13.921, 14.94, 15.359, 16.26, 16.639, 17.36, 19.08, 20.321, 21.961, 22.381, 24.118, 25.42, 27.441, 28.381, 29.321, 29.799, 32.675, 33.14, 33.563, 33.923, and 41.6.  The Baricitinib crystal form A can be applied in the drugs for prevention and ............

Clip

Crystalline forms of 1 ethylsulfonyl 3 4 7H pyrrolo 2 3 d pyrimidin 4 yl ...

priorart.ip.com/IPCOM/000244270
 
Nov 27, 2015 - Crystalline forms of baricitinib were found and are described ... on their appearance temperature As follows the polymorph observed at room ...

Mp. 213.8 °C (DSC).
IR (KBr): 3203, 3116, 2256, 1583, 1328, 1138 cm-1.

HNMR (DMSO-d6, 400 MHz): δ 12.17 (bs, 1H), 8.95 (s, 1H), 8.73 (s, 1H), 8.50 (s, 1H), 7.64
(d, J=3.2 Hz, 1H), 7.10 (d, J=3.4 Hz, 1H), 4.62 (d, J=9.0 Hz, 2H), 4.26 (d, J=9.1 Hz,
2H), 3.72 (s, 2H), 3.26 (q, J=7.3 Hz, 2H), 1.26 (t, J=7.3 Hz, 3H) ppm.

CNMR (DMSO-d6, 100 MHz): δ 152.39, 151.10, 149.55, 140.10, 129.80, 127.13, 122.42,
116.86, 113.25, 100.14, 58.74, 56.26, 43.50, 27.03, 7.63 ppm.
HSQC (optimized for JC-H = 145 Hz): 8.95-129.80, 8.73-151.10, 8.50-140.10, 7.64-127.13,
7.10-100.14, 4.62-58.74, 4.26-58.74, 3.72-27.03, 3.26-43.50, 1.26-7.63.

HMBC (optimized for JC-H = 8 Hz): 12.17-(127.13, 113.25, 100.14), 8.95-(140.10, 122.42,
56.26), 8.73-(152.39, 149.55, 113.25), 8.50-(129.80, 122.42), 7.64-(152.39, 113.25,
100.14), 7.10-(152.39, 127.13, 113.25), (4.62, 4.26)-(58.74, 56.26, 27.03), 3.72-
(116.86, 58.74, 56.26), 3.26-7.63, 1.26-43.50.

Calcd. C16H17N7O2S (M 371.42):
C 51.74%; H 4.61%; N 26.40%; S 8.63%.
Found C 51.62%; H 4.59%; N 26.28%; S 8.78%.


References

  1.  “Baricitinib” (pdf). Statement on a nonproprietary name adopted by the USAN council. American Medical Association.
  2.  “Lilly, Incyte Treatment Shows Positive Results”.http://www.insideindianabusiness.com. 9 Dec 2014. Retrieved 2 Mar 2015.
PATENTSUBMITTEDGRANTED
AZETIDINE AND CYCLOBUTANE DERIVATIVES AS JAK INHIBITORS [US8158616]2009-09-172012-04-17
AZETIDINE AND CYCLOBUTANE DERIVATIVES AS JAK INHIBITORS [US2013225556]2013-03-292013-08-29
JANUS KINASE INHIBITORS FOR TREATMENT OF DRY EYE AND OTHER EYE RELATED DISEASES [US2010113416]2010-05-06
METHOD OF TREATING MUSCULAR DEGRADATION [US2013310340]2013-05-152013-11-21
METHOD OF SELECTING THERAPEUTIC INDICATIONS [US2014170157]2012-06-152014-06-19
CYCLODEXTRIN-BASED POLYMERS FOR THERAPEUTIC DELIVERY [US2014357557]2014-05-302014-12-04
Azetidine and cyclobutane derivatives as JAK inhibitors [US8420629]2011-12-092013-04-16
BIOMARKERS AND COMBINATION THERAPIES USING ONCOLYTIC VIRUS AND IMMUNOMODULATION [US2014377221]2013-01-252014-12-25
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US9206187Sep 6, 2013Dec 8, 2015Incyte Holdings CorporationHeteroaryl substituted pyrrolo[2,3-B] pyridines and pyrrolo[2,3-B] pyrimidines as Janus kinase
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str1
Baricitinib.svg
SYSTEMATIC (IUPAC) NAME
2-[1-ethylsulfonyl-3-[4-(7H-pyrrolo[2,3-d]pyrimidin-4-yl)pyrazol-1-yl]azetidin-3-yl]acetonitrile
CLINICAL DATA
LEGAL STATUS
  • Investigational
IDENTIFIERS
CAS NUMBER1187594-09-7
ATC CODENone
PUBCHEMCID: 44205240
CHEMSPIDER26373084
CHEMBLCHEMBL2105759
PDB LIGAND ID3JW (PDBeRCSB PDB)
CHEMICAL DATA
FORMULAC16H17N7O2S
MOLECULAR MASS371.42 g/mol





SEE..........http://newdrugapprovals.org/2013/06/17/lilly-and-partner-incyte-corp-have-presented-more-promising-data-on-their-investigational-jak-inhibitor-baricitinib-for-rheumatoid-arthritis/


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