Tofacitinib Citrate, 的合成 توفاسيتين يب Тофацитиниб トファシチニブ

 

TOFACITINIB

  托法替布

 3-{(3R,4R)-4-methyl-3-[methyl-(7H-pyrrolo[2,3-d]pyrimidin-4-yl)-amino]-piperidin-1-yl}-3-oxo-propionitrile citrate salt
CAS number: 540737-29-9

An Improved and Efficient Process for the Preparation of Tofacitinib Citrate

Yogesh S. Patil, Nilesh L. Bonde, Ankush S. Kekan, Dhananjay G. Sathe*1, and Arijit Das

Publication Date (Web): November 17, 2014 (Article)

DOI: 10.1021/op500274j

 http://pubs.acs.org/doi/full/10.1021/op500274j

 

MS m/z 313 (M⁺ + 1); 

mp 201–202 °C;  

¹H NMR (CDCl₃) δ 8.34 (s, 1H), δ 7.38 (d, 1H, J = 2.4 Hz), δ 6.93 (d, 1H, J = 2.4 Hz), δ 4.97 (m, 1H), δ 3.93–4.03 (m, 4H), δ 3.66 (m, 1H), δ 3.50 (m, 4H), δ 2.91 (d, 2H, J = 15.6 Hz), δ 2.80 (t, 2H, J = 12.8 Hz), δ 2.55 (m, 1H), δ 1.99 (m, 1H), δ 1.77 (m, 1H), δ 1.13–1.18 (m, 3H).
SEE.......http://newdrugapprovals.org/2015/07/24/tofacitinib-%E7%9A%84%E5%90%88%E6%88%90-spectral-visit/

NMR PREDICTION

H-NMR spectral analysis

CAS NO. 477600-75-2, (3R,4R)-4-methyl-3-(methyl-1H-pyrrolo[2,3-d]pyrimidin-4-ylamino)-β-oxo-1-piperidinepropanenitrile H-NMR spectral analysis

C-NMR spectral analysis

CAS NO. 477600-75-2, (3R,4R)-4-methyl-3-(methyl-1H-pyrrolo[2,3-d]pyrimidin-4-ylamino)-β-oxo-1-piperidinepropanenitrile C-NMR spectral analysis

SEEhttp://www.hoborchem.com/news/Chemical-Synthesis-of-Tofacitinib-Citrate-15.html

Synthesis conditions for Tofacitinib Citrate (Xeljanz, CP-690550-10)

a)potassium tert-butoxide, Dimethyl carbonate, 2-methyltetrahydrofuran; toluene, 87% yield
b)5% Rh/C (Johnson-Matthey type C101023-5), acetic acid, hydrogen, 72-78°C, 70-80 psi, 75% yield (92.7% cis by GC)
c)benzaldehyde, sodium triacetoxyborohydride, toluene, 73% yield (96.6% cis and 2.5% trans by GC)
d)lithium aluminum hydride, tetrahydrofuran
e)concentrated hydrochloric acid, isopropanol, 87% yield (99.3% cis and 0.7% trans by GC)
f)di-p-toluoyl-L-tartaric acid, sodium hydroxide, water, methanol,42% yield (98.6% enantiomeric excess, 0.6% trans isomer by GC)
g)2,4-dichloro-7H-pyrrolo[2,3-d]pyrimidine, potassium carbonate,water, 95-105° C, 100% yield
h)20 weight% palladium hydroxide on carbon (50% water wet), water, hydrogen,70-75°C, 50 psi
i)ethyl cyanoacetate, 1-butanol,1,8-diazabicyclo[5.4.0]-undec-7-ene(DBU),40 °C, 20 h
j)citric acid monohydrate, water, 1-butanol, 81 °C, 93% yield

References:

Procedures (a) to (e) 

Weiling Cai, James L. Colony,Heather Frost, James P. Hudspeth, Peter M. Kendall, Ashwin M. Krishnan,Teresa Makowski, Duane J. Mazur, James Phillips, David H. Brown Ripin, Sally Gut Ruggeri, Jay F. Stearns, and Timothy D. White; Investigation of Practical Routes for the Kilogram-Scale Production of cis-3-Methylamino-4-methylpiperidines; Organic Process Research & Development 2005, 9, 51−56

Ripin, D. H.B.; 3-amino-piperidine derivatives and methods of manufacture, US patent application publication, US 2004/0102627 A1

Procedures  (f) to (h)

Ruggeri, Sally, Gut;Hawkins, Joel, Michael; Makowski, Teresa, Margaret; Rutherford, Jennifer, Lea; Urban,Frank,John;Pyrrolo[2,3-d]pyrimidine derivatives: their intermediates and synthesis, PCT pub. No. WO 2007/012953 A 2, US20120259115 A1, United States Patent US8232393. Patent Issue Date: July 31, 2012

Procedures (i) to (j)

Kristin E. Price, Claude Larrive´e-Aboussafy, Brett M. Lillie, Robert W. McLaughlin, Jason Mustakis, Kevin W. Hettenbach, Joel M. Hawkins, and Rajappa Vaidyanathan; Mild and Efficient DBU-Catalyzed Amidation of Cyanoacetates, Organic Letters, 2009, vol.11, No.9, 2003-2006

Detailed production procedures for the synthesis of Tofacitinib Citrate (Xeljanz, CP-690550-10) SEEhttp://www.hoborchem.com/news/Chemical-Synthesis-of-Tofacitinib-Citrate-15.html

a
Preparation of 4-methyl-pyridin-3-yl)-carbamic acid methyl ester  (3-Methoxycarbonylamino-4-methylpyridine)  

To a clean, dry, nitrogen-purged 800 L reactor were charged 3-amino-4-methylpyridine (49.9 kg, 461 mol) and 2-methyltetrahydrofuran (383 L). The reaction was heated to 32- 38 °C for at least 90 min. To a clean, dry, nitrogen-purged 2000 L reactor were charged potassium tert-butoxide (104.0 kg, 927 mol) and 2-methyltetrahydrofuran (255 L). The reaction was stirred at 23-27 °C for at least 30 min to break up the potassium tert-butoxide. Dimethyl carbonate (49.9 kg, 554 mol) was added to the slurry of potassium tert-butoxide at a rate that maintained the temperature below 35 °C. The 3-amino-4-methylpyridine solution was added to the 2000 L reactor at a rate that maintained the temperature from 20 to 35 °C. An additional 115 L of 2-methyltetrahydrofuran was added to aid stirring. The mixture was stirred between 20 and 35 °C for at least 2 h. The reaction was sampled and checked for completion by GC, then cooled to 15-20 °C. Water (255 L) was added at a rate to maintain the temper-ature below 25 °C. The mixture was stirred for at least 30 min then allowed to settle for at least 60 min. The phases were separated, and 2-methyltetrahydrofuran (255 L) was added to the aqueous layer. The reaction mixture was allowed to stir for at least 60 min and then allowed to settle for at least 60 min. The phases were separated, and the 2-meth-yltetrahydrofuran layers were combined. Darco KBB (10.0 kg) was added to the organic layer and allowed to stir for at least 30 min. The Darco slurry was filtered through a bed of Celite, and the cake was washed with 2-methyltetrahydro-furan (51 L). The 2-methyltetrahydrofuran was displaced with toluene under vacuum to a final volume of 480-540 L, then the mixture was cooled to 23-27 °C over at least 90 min. After sampling to ensure that the water content was <1%, the slurry was stirred for at least 12 h. The resulting solids were filtered and washed with toluene (212 L). After drying under vacuum at 40-50 °C for at least 12 h with a slight nitrogen bleed, 66.5 kg (400 mol) of (4-methyl-pyridin- 3-yl)carbamic acid methyl ester was isolated in 86.7% yield (99.89% purity by HPLC) mp: 115.3-116.6 °C. 1H NMR (400 MHz, DMSO): ä 9.12 (bs, 1H), 8.46 (s, 1H), 8.18 (d, J ) 4.9 Hz, 1H), 7.20 (d, J ) 4.9 Hz, 1H), 3.64 (s, 3H), 2.19 (s, 3H). 13C NMR (DMSO): 155.6, 146.5, 146.3, 141.4, 134.2, 125.9, 52.6, 17.8. Anal. Calcd for C8H10N2O2:C, 57.82; H, 6.07; N, 16.86. Found: C, 57.71; H, 5.80; N, 16.85.

b

Preparation of cis-3-Methoxycarbonylamino-4-methylpiperidine SEEhttp://www.hoborchem.com/news/Chemical-Synthesis-of-Tofacitinib-Citrate-15.html

To a clean, nitrogen-purged 1200 L reactor were charged Darco KBB14 (6.6 kg), (4-methyl-pyridin-3-yl)carbamic acid methyl ester (66.5 kg) and acetic acid (677 L). The mixture was stirred for at least 30 min at 20-30 °C and filtered through a bed of Celite, and the cake was washed with acetic acid (135 L). To a clean, nitrogen-purged 2000 L hydrogena-tion reactor were charged 5% Rh/C (Johnson-Matthey type C101023-5, 16.5 kg) and the (4-methyl-pyridin-3-yl)carbamic acid methyl ester acetic acid solution. The reaction was stirred for at least 15 min and then purged sequentially with nitrogen and hydrogen. The reaction was heated to 72-78 °C and then pressurized with hydrogen gas at 70-80 psig. The reaction was allowed to stir under these conditions until hydrogen uptake ceased. A sample was obtained for reaction completion check by GC. The reaction was purged with nitrogen, and the catalyst was filtered on a water-wet Celite-coated filter. The cake was washed with toluene (212 gal), and the filtrates were combined. The solution of (4-methyl-pipridin-3-yl)carbamic acid methyl ester (92.7% cis by GC) was used in the next step without further purification. In the lab, an aliquot (0.50 g) of the reduced product was purified via silica gel chromatography (20% EtOAc-hexanes) to yield purified product (0.38 g). The purified product was dissolved in IPE (10 mL) and treated with bubbling HCl gas. The white solid was filtered and dried under vacuum to yield a white solid (11.9 g, 75%) mp 199-200.5 °C. Rf freebase) ) 0.21 (5:1 CH2Cl2-CH3OH). Anal. Calcd for C8H17ClN2O2: C,46.04; H, 8.21; N, 13.42. Found: C, 46.93; H, 8.84; N, 12.29. 1H NMR (HCl salt) (400 MHz, CD3OD): ä 6.94 (bs, 1H), 3.95 (m, 1H), 3.66 (m, 4H), 3.38 (dd, J ) 13.27, 4.15, 1H), 3.28 (m, 1H), 3.14 (dd, J ) 13.27, 3.11, 1H), 3.05 (ddd, J ) 12.85, 9.95, 4.56 1H), 2.07 (m, 1H), 1.74 (m, 2H), 1.01 (d, J ) 7.05, 3H). 13C NMR (300 MHz, CD3OD): ä 158.0, 51.6, 48.7, 46.7, 42.9, 31.1, 25.6, 15.1.

c

Preparation of  cis-N-Benzyl-3-methoxycarbonylamino-4-methylpipe-ridine HydrochlorideSEEhttp://www.hoborchem.com/news/Chemical-Synthesis-of-Tofacitinib-Citrate-15.html

To a clean, nitrogen-purged 2000 L reactor was charged (4-methyl-piperidin-3-yl)carbamic acid methyl ester as the crude acetic acid and toluene solution from the previous step. The acetic acid was displaced with toluene under vacuum to a final volume of 500-560 L. The reaction was cooled and a sample pulled to check for an acetic acid content of <4% as determined by 1H NMR. Benzaldehyde (46.4 kg, 437 mol) was added to the reaction at 20-30 °C and stirred for at least 30 min. To a clean, dry, nitrogen-purged reactor were charged sodium triacetoxy-borohydride (92.6 kg, 437 mol) and toluene (472 L). The mixture was allowed to stir for at least 60 min at 20-30 °C. The benzaldehyde solution was transferred to the sodium triacetoxyborohydride reactor at a rate that maintained the temperature from 20 to 30 °C, then the reaction was stirred for at least 2 h. The reaction was sampled and checked for completion by GC. It was quenched by addition of a solution of 50% aqueous sodium hydroxide (158.9 kg diluted with 352 gal of water), maintaining the temperature at 20-30 °C, until a pH between 6 and 7 was achieved. The reaction was then stirred for at least 60 min and allowed to settle for at least 60 min, and the phases were separated. The toluene layer was heated to 70-80 °C, and concentrated HCl (47.0 kg, 477 mol) was added over at least 30 min. The reaction was held from 70 to 80 °C for at least 60 min. The reaction was cooled to 15-25 °C over at least 60 min and held for at least 2 h. The resulting solids were filtered, and the cake was washed with toluene (190 L). After drying under vacuum at 40-50 °C for at least 12 h with a slight nitrogen bleed, cis-N-benzyl-3-methoxycarbonylamino-4-methylpiperidine hy-drochloride (86.8 kg, 290 mol) was isolated in 73.1% yield over two steps (96.6% cis and 2.5% trans by GC) mp: 187.3-191.4 °C. 1H NMR (400 MHz, CDCl3): ä 12.11 (bs, 1H), 7.57-7.52 (m, 3H), 7.43-7.39 (m, 3H), 4.26 (dd, J ) 13.3, 4.6 Hz, 1H), 4.16 (bd, J ) 9.9 Hz, 1H), 4.07 (dd, J ) 13.3, 5.8 Hz, 1H), 3.60 (s, 3H), 3.49 (bd, J ) 12.0 Hz, 1H), 3.29 (dd, J ) 12.9, 2.1 Hz, 1H), 2.89 (ddd, J ) 12.9, 10.8, 3.3 Hz, 1H), 2.74 (dddd, J ) 12.4, 12.0, 9.5, 2.9 Hz, 1H), 2.22 (dddd, J ) 13.3, 13.0, 12.4, 3.9 Hz, 1H), 1.82-1.74 (m, 1H), 1.64 (bd, J ) 13.0 Hz, 1H), 0.94 (d, J ) 6.6 Hz, 3H). 13C NMR (CDCl3): 157.8, 131.8, 130.5, 129.6, 127.9, 61.3, 56.8, 53.1, 52.5, 48.6, 32.6, 26.2, 17.2. Anal. Calcd for C15H23ClN2O2: C, 60.29; H, 7.76; N, 9.38. Found: C, 60.21; H, 7.83; N, 9.29.

d

Preparation of cis-N-Benzyl-3-methylamino-4-methypiperidine Bis-(hydrochloride)SEEhttp://www.hoborchem.com/news/Chemical-Synthesis-of-Tofacitinib-Citrate-15.html

To a clean, dry, nitrogen-purged 2000 L reactor were charged (1-benzyl-4-methyl-piperidin-3-yl)-carbamic acid methyl ester hydrochloride (41.9 kg, 140 mol) and tetrahydrofuran (685 L). The reactor was purged three times with nitrogen and allowed to stir for at least 45 min at 20-30 °C to break up the solids. A sample was pulled to ensure that the water content was <0.2% water. The reaction was cooled to between -15 to 5 °C, and a 1.0 M solution of lithium aluminum hydride in tetrahydrofuran (181.4 kg, 200 mol) was added at a rate to maintain the temperature from -15 to 5 °C. The charge line was rinsed with tetrahydrofuran (19 gal), and the reaction was heated and held at reflux for at least 2.5 h. After cooling to 20-30 °C, the reaction was sampled and checked for completion by GC. The reaction was cooled to between -10 and 5 °C and a chilled (-10 to 5 °C) solution of tetrahydrofuran (43 L) and water (16.3 kg) was added at a rate to maintain the temperature at -10 to 5 °C with slight nitrogen bleed. The reaction was then heated to 20-25 °C over at least 60 min and purged with nitrogen to remove any traces of hydrogen. The resulting aluminum solids were filtered and washed with tetrahydrofuran (2 86 L). The tetrahydrofuran was displaced with 2-propanol until a temperature of at least 78 °C and a reaction volume was of 460-540 L were achieved. The reaction was cooled to 65-75 °C, and concentrated HCl (28.9 kg, 294 mol) was added over at least 60 min. The displacement was continued until additional 2-propanol (1060 L) was added and the final temp was at least 81 °C and the final volume was 390-460 L. The reaction was cooled to between 65 and 75 °C and granulated for at least 2 h. The reaction was cooled to between 15 and 25 °C, and a sample was pulled to ensure that the water content was <1%. After stirring at least2hat15-25 °C, the solids were filtered and washed with 2-propanol (85 L). After drying under vacuum for at least 12 h at 40-50 °C with a slight nitrogen bleed (cis-N-benzyl-3-methylamino-4-methypiperidine bis-(hydrochloride) (35.5 kg, 122 mol) was isolated in 87.1%yield (99.3% cis and 0.70% trans by GC) mp: 261.3-267.0 °C. 1H NMR (400 MHz, 1:1 CD3CN:D2O): ä 7.51-7.43 (m, 5H), 4.36-4.27 (m, 2H), 3.62-3.59 (m, 2H), 3.24- 3.13 (m, 3H), 2.65 (s, 3H), 2. (m, 1H), 1.95-1.91 (m, 1H), 1.82-1.75 (m, 1H), 1.03 (d, J ) 7.5 Hz, 3H). 13C NMR (1:1 CD3CN:D2O): 131.8, 130.5, 129.6, 128.6, 118.7, 61.0, 55.8, 46.4, 31.3, 27.5, 26.0, 10.0. Anal. Calcd for C14H24-Cl2N2: C, 57.73; H, 8.31; N, 9.62. Found: C, 57.77; H, 8.30; N, 9.60.

e

Preparation of bis-(3R,4R)-(1-benzyl-4-methyl-piperidine-3-yl)-methylamine di-p-toluoyl-L-tartaric acidSEEhttp://www.hoborchem.com/news/Chemical-Synthesis-of-Tofacitinib-Citrate-15.html

To a clean, dry, nitrogen-purged 250 ml flask were charged racemic cis-(1-benzyl-4-methyl-piperidine-3-yl)-methylamine bis hydrochloride (20.0 g, 68.7 mmol), di-p-toluoyl-L-tartaric acid (L-DPTT) (15.9 g, 41.2 mmol) and methanol (100 ml). A solution of sodium hydroxide (5.5 g, 137.3 mmol in water (100 ml)) was added to the reaction at a rate to maintain the temperature below 30° C. The reaction was heated to between 70-80° C. and held at this temperature for at least 60 minutes. The reaction was cooled to 5-15° C. over at least 4 hours and held at this temperature for at least 12 hours. The solids were filtered and washed with a 1:1 mixture of MeOH:water (60 ml). The wet-cake was returned to the 250 ml flask and methanol (100 ml) and water (100 ml) were charged. The reaction was heated to between 70-80° C. and held at this temperature for at least 120 minutes. The reaction was cooled to 5-15° C. over at least 4 hours and held at this temperature for at least 12 hours. The solids were filtered and washed with a 1:1 mixture of MeOH:water (60 ml). The wet-cake was sampled for purity (99.4% ee) to ensure an additional repulp was not necessary. After drying under vacuum at 40-50° C. for at least 24 hours with a slight nitrogen bleed, the title compound (11.9 g, 28.9 mmol) was isolated in 42.1% yield (98.6% enantiomeric excess, 0.63% trans isomer by GC (Cyclosil B column 30 m×I.D. 0.25 mm; Inlet Temp 250; 2.0 ml/min flow rate; 15 min run; 160 C isothermal method.

f

Preparation of N-[(3R,4R)-1-benzyl-4-methylpiperidin-3-yl]-2-chloro-N-methyl-7H-pyrrolo[2,3-d]pyrimidin-4-amine SEEhttp://www.hoborchem.com/news/Chemical-Synthesis-of-Tofacitinib-Citrate-15.html

To a clean, dry, nitrogen-purged 500 ml reactor were charged 2,4-dichloro-7H-pyrrolo[2,3-d]pyrimidine, prepared as described below, (20.0 g, 0.106 mol), bis-(3R,4R)-(1-benzyl-4-methyl-piperidine-3-yl)-methylamine di-p-toluoyl-L-tartaric acid (20 g, 0.106 mol), potassium carbonate (44.6 g, 0.319 mol) and water (200 ml). The reactor was heated to 95-105° C. for a minimum of 10 hours then cooled to 20-30° C. and held for a minimum of 3 hours. The resulting solids were isolated by filtration, washed with water (60 ml) and dried at 50° C. to afford 39.5 g (100%) of the title compound.

Anal. Calcd. for C20H24ClN5: C, 64.94; H, 6.54; N, 18.93; Found: C, 64.78; H, 6.65; N, 18.83. 1H NMR (400 MHz, d6-acetone): δ 10.80 (bs, 1H), 7.36 (d, J=7.0 Hz, 2H), 7.30 (t, J=7.0 Hz, 2H), 7.24-7.20 (m, 1H), 7.13 (d, J=3.7 Hz, 1H), 6.66 (bs, 1H), 5.15 (bs, 1H), 3.69 (bs, 3H), 3.54 (ABq, J=13.3 Hz, 1H), 3.50 (ABq, J=13.3 Hz, 1H), 2.92 (dd, J=12.0, 5.4 Hz, 1H), 2.88-2.83 (m, 1H), 2.77 (bs, 1H), 2.64-2.59 (m, 1H), 2.29 (bs, 1H), 2.16 (bs, 1H), 1.75-1.69 (m, 2H), 0.94 (d, J=6.6 Hz, 3H). 13C NMR (400 MHz, d6-DMSO, mixture of Isomers): 158.0, 152.5, 151.8, 138.3, 129.1, 128.6, 128.1, 127.6, 126.8, 121.0, 102.3, 100.8, 62.5, 54.6, 53.1, 50.8, 35.3, 32.0, 30.9, 15.3.

g

Preparation of 2,4-dichloro-7H-pyrrolo[2,3-d]pyrimidineSEEhttp://www.hoborchem.com/news/Chemical-Synthesis-of-Tofacitinib-Citrate-15.html

A reactor was equipped with 7H-pyrrolo[2,3-d]pyrimidine-2,4-diol(10.0g, 66.2 mmol) and toluene (30 ml) with stirring. Phosphorusoxychloride (18.5 ml, 198.5 mmol) was added and the reactor was warmed to 700C. Diisopropylethylamine (23.0 m, 132.3 mmol) was added over 2.5 h to control the exotherm. After completion of the base addition, the reactor was heated to 1060C and stirred at temperature for 16 h. The mixture was cooled to 250C and added slowly to a flask containing water (230 ml) and ethyl acetate (120ml) at room temperature, then stirred overnight at room temperature. After filtration through Celite, the layers were separated the aqueous layer was extracted with ethyl acetate (3 x 75ml). The organic layers were combined and washed with brine (100ml). Darco KBB (1.24 g) was added to the organics, then filtered through Celite and dried over sodium sulfate (10.0 g). The solution was concentrated in vacuo to obtain the title compound (52% yield).


h

Preparation of methyl-[(3R,4R)-4-methyl-piperidin-3-yl]-(7H-pyrrolo[2,3-d]pyrimidin-4-yl)amineSEEhttp://www.hoborchem.com/news/Chemical-Synthesis-of-Tofacitinib-Citrate-15.html

To a clean, dry, nitrogen-purged 500 ml hydrogenation reactor were charged 20 wt % Pd(OH)2/C (palladium hydroxide on carbon) (5.0 g, 50% water wet), water (200 ml), and N-((3R,4R)-1-benzyl-4-methylpiperidin-3-yl)-2-chloro-N-methyl-7H-pyrrolo[2,3-d]pyrimidin-4-amine (50.0 g, 0.135 mol). The reactor was purged three times at 50 psi with nitrogen and three times at 50 psi with hydrogen. Once purging was complete, the reactor was heated to 70-75° C. and pressurized to 50 psi with hydrogen through a continuous feed. The hydrogen uptake was monitored until no hydrogen was consumed for a minimum of 1 hour. The reactor was cooled to 20-30° C. and purged three times at 50 psi with nitrogen. The reaction mixture was filtered through water-wet Celite and transferred to a clean, dry, nitrogen-purged 500 ml reactor for subsequent processing.

Mp 158.6-159.8° C. 1H NMR (400 MHz, CDCl3): δ 11.38 (bs, 1H), 8.30 (s, 1H), 7.05 (d, J=3.5 Hz, 1H), 6.54 (d, J=3.5 Hz, 1H), 4.89-4.87 (m, 1H), 3.39 (s, 3H), 3.27 (dd, J=12.0, 9.3 Hz, 1H), 3.04 (dd, J=12.0, 3.9 Hz, 1H), 2.94 (td, J=12.6, 3.1 Hz, 1H0, 2.84 (dt, J=12.6, 4.3 Hz, 1H), 2.51-2.48 (m, 1H), 2.12 (bs, 2H), 1.89 (ddt, J=13.7, 10.6, 4 Hz, 1H), 1.62 (dq, J=13.7, 4Hz, 1H), 1.07 (d, J=7.3 Hz, 3H). 13C NMR (400 MHz, CDCl3): δ 157.9, 152.0, 151.0, 120.0, 103.0, 102.5, 56.3, 46.2, 42.4, 34.7, 33.4, 32.4, 14.3.

i

Preparation of 3-{(3R,4R)-4-methyl-3-[methyl-(7H-pyrrolo[2,3-d]pyrimidin-4-yl)-amino]-piperidin-1-yl}-3-oxo-propionitrile citrate salt (Tofacitinib citrate, Xeljanz, CP-690550-10) SEEhttp://www.hoborchem.com/news/Chemical-Synthesis-of-Tofacitinib-Citrate-15.html

To a round-bottomed flask fitted with a temperature probe, condenser, nitrogen source, and heating mantle, methyl-[(3R,4R)-4-methyl-piperidin-3-yl]-(7H-pyrrolo[2,3-d]pyrimidin-4-yl)-amine (5.0 g, 20.4 mmol) was added followed by 1-butanol (15 mL), ethyl cyanoacetate (4.6 g, 40.8 mmol), and DBU (1.6 g, 10.2 mmol). The resulting amber solution was stirred at 40 °C for 20 h. Upon reaction completion, citric acid monohydrate (8.57 g, 40.8 mmol) was added followed by water (7.5 mL) and 1-butanol (39.5 mL). The mixture was heated to 81 °C and held at that temperature for 30 min. The mixture was then cooled slowly to 22 ºC and stirred for 2 h. The slurry was filtered and washed with 1-butanol (20 mL). The filter cake was dried in a vacuum oven at 80 °C to afford 9.6 g (93%) of tofacitinib citrate as an off-white solid.

1H NMR (500 MHz, d6-DMSO): δ 8.14 (s, 1H), 7.11 (d, J=3.6 Hz, 1H), 6.57 (d, J=3.6 Hz, 1H), 4.96 (q, J=6.0 Hz, 1H), 4.00-3.90 (m, 2H), 3.80 (m, 2H), 3.51 (m, 1H), 3.32 (s, 3H), 2.80 (Abq, J=15.6 Hz, 2H), 2.71 (Abq, J=15.6 Hz, 2H), 2.52-2.50 (m, 1H), 2.45-2.41 (m, 1H), 1.81 (m, 1H), 1.69-1.65 (m, 1H), 1.04 (d, J=6.9 Hz, 3H).

 SEE.......http://newdrugapprovals.org/2015/07/24/tofacitinib-%E7%9A%84%E5%90%88%E6%88%90-spectral-visit/

....................

Synthesis   of   Tofacitinib

ZHANG   Zhongkui,   KUANG   Chunxiang*

(Dept.   ofChemistry,   Tongji   University,   Shanghai   200092)

   Tofacitinib,   ananti-rheumatoid   arthritis   drug,   was   synthesized   from   N-[(3R,4R)-1-benzyl-4-methylpiperidin-3-yl]-N-methyl-7H-pyrrolo[2,3-d]pyrimidin-4-amine(7)   by   removing   the   benzyl   group   andcondensing   with   ethyl   cyanoacetate   in   one-pot   synthesis.   The   intermediate   7   could   be   obtainedfrom   4-chloro-7H-pyrrolo[2,3-d]pyrimidine(2)   by   protection,   substitution   and   deprotection.   The   totalyield   of   tofacitinib   was   about   57％(based   oncompound   2)   with   purity   of   99.4％.

SEE.......http://newdrugapprovals.org/2015/07/24/tofacitinib-%E7%9A%84%E5%90%88%E6%88%90-spectral-visit/

1H NMR

SEE.......http://newdrugapprovals.org/2015/07/24/tofacitinib-%E7%9A%84%E5%90%88%E6%88%90-spectral-visit/

13C NMR PREDICT

 1H NMR picture from the net........not mine


 

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Development of Safe, Robust, Environmentally Responsible Processes for New Chemical Entities
- Dr. V. Rajappa, Director & Head-Process R&D, Bristol-Myers Squibb, India

A PRESENTATION





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GOA INDIA

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Goa is visited by large numbers of international and domestic tourists each year for its beaches, places of worship and world heritage architecture. It also has ...

‎Vasco da Gama - ‎Indian annexation of Goa - ‎Tourism in Goa - ‎Portuguese India

ANJUNA






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SEASGOA MINE





















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Take a tour
SOLOMON ISLANDS



HONIARA





Malaita, Solomon Islands ...









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Gizo, on Ghizo Island, is the capital of the Solomon Islands’ far-flung Western Province, a paradise of coral cays, atolls, lagoons and volcanic islands east of Papua New Guinea where, on a rainy day in late July, crowds flocked to the local netball court for the opening of the inaugural Akuila Talasasa Arts Festival.

Motorised canoes lined up in Gizo Harbour near the daily marketplace.










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The power of NMR: in two and three dimensions

In Short

• Two dimensional NMR experiments use a sequence of two or more pulses with a variable time delay to generate spectra 
• COSY spectra clarify where the protons are in a molecule 
• Two and three dimensional NMR are used to solve protein structureS
• 
  

Soon after its discovery in the 1950s, NMR had become an indispensable tool for chemists. In the 1970s and 1980s, the power of the technique was extended from one dimension to two and even three dimensions, opening up exciting applications in both chemistry and biochemistry. Geoff Brown 

The success of one dimensisnal, high-resolution NMR stems from the unique insights that it can provide about molecular structure.¹  The chemical shift of a nucleus gives invaluable information about the chemical environment in which that nucleus is located. Coupling interactions between hydrogen nuclei, as revealed by characteristic splitting patterns in the ¹H-nmr spectrum, provide information about the location of one group of hydrogen atoms relative to others in the molecule. And the nuclear Overhauser effect (nOe) can shed light on molecular stereochemistry.  

The concept of two dimensional NMR spectroscopy was first put forward in 1971 by Belgian scientist Jean Jeener, working at the Université Libre de Bruxelles.²  The principles behind this technique evolved naturally from the pulsed-Fourier transform (FT) experiment, but what benefits has this technique brought?^3,4 

Two dimensional NMR  

In the one dimensional pulsed-FT experiment, a spinning nucleus is placed in a magnetic field; it is then excited from a lower energy state to a higher state by a pulse of radiofrequency radiation. This pulse generates a simultaneous response from all the different resonances which are present in the molecule, and these responses must then be disentangled from one another, by a Fourier transformation, to produce an nmr spectrum.  

In the corresponding two dimensional NMR experiments, excitation is achieved by a sequence of two or more pulses. In addition, there is one (or more) variable delay period between these pulses. To generate the second dimension, this pulse sequence is repeated many times, and the length of the variable delay is increased each time. After Fourier transformation, we obtain a dataset which consists of a series of one dimensional nmr spectra. Each spectrum differs subtly from its predecessor, as a result of changes which have occurred during the incremental delay.  

Fig 1 The 1H-1H COSY spectrum of the amonio acid isoleucine

By applying a second Fourier transformation to the dataset, along the 'axis' of the variable delay, and therefore orthogonal to the first transformation, we obtain the two dimensional nmr spectrum. This spectrum retains the chemical shift information of the one dimensional nmr spectrum along the horizontal axis (obtained from the first Fourier transformation) as well as providing new information about a second nmr parameter in the vertical dimension (the new dimension 'reports' solely on whatever kind of 'evolution' has occurred during the incremental delay as revealed by the second Fourier transformation). The strength of two dimensional NMR spectroscopy is its ability to provide 'correlations' between any two sets of nmr parameters, enabling couplings or nOes to be established in a more efficient or less ambiguous way than was previously possible.  

COSY for chemists 

Hundreds of two dimensional NMR experiments have been described over the past 20 years, all of which are designed around the same basic principles: ieall contain multiple pulses and at least one variable inter-pulse delay. However, only a handful of these techniques have stood the test of time and continue to find routine application today.  

The most commonly-encountered modern two dimensional NMR technique is homonuclear shift-correlation spectroscopy (COSY), which presents ¹H chemical shift data on both the horizontal and vertical axes. The COSY experiment establishes 'connections' between protons via their mutual couplings, as shown in Fig 1  (the two dimensional COSY spectrum of the amino acid, isoleucine). The most easily attributable hydrogen resonance in the one dimensional ¹H-nmr spectrum of isoleucine (Fig 2) is the -proton at 3.5 ppm.¹ This proton has a characteristic chemical shift, owing to the substitution of a nitrogen atom at the methine carbon (protons attached to a carbon bearing such an electronegative atom have a predictable chemical shift in the 3-5 ppm range).  

As expected, the -proton in Fig 2 is also split into two peaks, as a result of coupling to the single proton in the neighbouring CH group (explained by the ' n+1' rule ).¹  However, it is not immediately obvious which peak in the one dimensional ¹H-nmr spectrum of isoleucine corresponds to this CH neighbour, nor is it trivial to continue the analysis of this spectrum any further past this point in the molecule. 

Fig 2 The 1H-nmr spectrum of isoleucine

Fortunately, the two dimensional ¹H-¹H COSY spectrum of isoleucine provides direct answers to these questions, without requiring a lengthy analysis of all the complex splitting patterns presented by the remaining protons in the rest of the molecule. To interpret the two dimensional nmr spectrum (Fig 1), first draw a line horizontally, starting from the -proton of isoleucine, which resonates at 3.5 ppm in both dimensions of the 'diagonal' (running from bottom left to top right). This line intersects an 'off-diagonal' peak at 1.9 ppm (red lines), thus revealing this to be the chemical shift of the adjacent methine hydrogen (which is coupled to the -proton through three bonds). The same process can be repeated twice more to assign all the other proton chemical shifts in isoleucine.  

Thus, if a second line is drawn horizontally, this time starting from the diagonal at 1.9 ppm, a further three 'connections' are revealed to adjacent protons at 1.3, 1.1 and 0.9 ppm (blue lines). The protons at 0.9 ppm correspond to the attached methyl group, which is a doublet. The protons at 1.3 and 1.1 ppm are associated with the next CH₂ in the chain. Both of these protons share further couplings with the second methyl group at the end of the chain (a triplet centred at 0.8 ppm), as indicated by the green lines in Fig 1. This then completes the 'connection' of all the hydrogen atoms in isoleucine - without reference to splitting patterns or chemical shift. 

Other two dimensional experiments 

Other useful two dimensional NMR experiments include the family of heteronuclear correlation experiments: ¹³C-¹H COSY, HSQC, HMQC and HMBC. All of these connect the chemical shifts of two different nuclei (most commonly ¹³C and ¹H), which are represented on separate axes of the two dimensional plot.  

Fig 3 One dimensional 13C-nmr spectrum of isoleucine

Figure 3 shows the one dimensional ¹³C-nmr spectrum of isoleucine, which presents six resonances, one for each carbon. Figure 4 illustrates the corresponding ¹³C-¹H COSY spectrum with the one dimensional ¹³C-nmr spectrum superimposed on the horizontal axis and a one dimensional ¹H-nmr spectrum projected along the vertical axis. (Note that the carbon peak at 175 ppm, corresponding to the carboxylic acid group, has not been included in the plot because it has no hydrogens directly attached.)  

As for the homonuclear proton-proton COSY experiment, the analysis of a heteronuclear correlation experiment is a straightforward matter, requiring horizontal and vertical lines to be drawn to 'connect' together ¹³C and ¹H resonances. Thus, moving horizontally across the ¹³C-¹H COSY spectrum at a proton chemical shift of 3.5 ppm leads to an intersection with a peak located at 60 ppm in the 'second' (¹³C) dimension, as shown by the red lines in Figure 4. Because this experiment has been set up to detect carbons and protons which are connected to one another by a single bond, the interpretation of this two dimensional nmr correlation is that the resonance appearing at 60 ppm in the ¹³C-nmr spectrum must correspond to the   -carbon.  

Admittedly, we might have predicted this assignment, based on the knowledge that the chemical shift of a functional group in ¹³C-nmr is roughly 20 times the corresponding ¹H chemical shift. However, it would be difficult to assign conclusively any of the remaining four carbon resonances in Figure 4 by looking at the one dimensional ¹³C-nmr spectrum alone.  

Fig 4 13C-1H COSY spectrum of isoleucine with one dimensional 13C- and 1H-nmr spectra superimposed on horizontal and vertical axes respectively

Since all the proton assignments for isoleucine are already known from analysis of the ¹H-¹H COSY spectrum (Fig 1), it is relatively easy to assign each of these carbon resonances, based on the known chemical shifts of the attached hydrogens. Thus, the blue lines in Fig 4 identify the carbon at 36 ppm as belonging to the next CH in the chain - because it is bonded to the hydrogen at 1.9 ppm. Similarly, the green lines show that the carbon at 25 ppm is bonded to two hydrogens at 1.1 and 1.3 ppm, thereby proving this to be the next CH₂  in the chain. (I leave the ¹³C assignments of the remaining two methyl groups, at 11 and 15 ppm for the reader.) 

The third two dimensional NMR experiment to find routine use in solving the structure of organic compounds is nuclear Overhauser enhancement spectroscopy (NOESY). This technique measures nuclear Overhauser enhancements (nOes) for protons which are spatially close to one another in a format which appears superficially similar to that of COSY. 

However, the pattern of off-diagonal peaks in the NOESY experiment provides information about the arrangement of hydrogen atoms in space, rather than the pattern of their covalent bonding. When NOESY is used in conjunction with the foregoing two dimensional NMR experiments, it is often possible to obtain enough information and constraints about the relationships between all the ¹H and ¹³C nuclei in a molecule of unknown structure, so that only one molecular structure is logically permissible. 

Protein NMR spectroscopy in three dimensions 

A protein is a linear polymer of amino acids (eg isoleucine) which are joined together by peptide bonds (see Fig 5). Proteins are typically several orders of magnitude larger than the small organic molecules for which the original two dimensional NMR experiments were designed. However, proteins are constructed from the same elements as small organic molecules: primarily, hydrogen, carbon, nitrogen and oxygen, so the same nmr theory applies.  

The main difficulty in analysing the one dimensional ¹H-nmr spectrum of a protein is that it contains a very large number of peaks crowded into a narrow chemical shift range between 0-10 ppm. This inevitably results in a high degree of accidental peak overlap. As a result, it is necessary to apply multidimensional NMR techniques (two-, three- and even four-dimensions) to the study of proteins. The higher dimensions effectively 'spread' these congested resonances out over a much larger area (for two dimensional NMR), or volume (for three dimensional NMR) - thereby drastically reducing the probability of accidental peak overlap. 

Fig 5 The 'backbone' of a protein from an NMR viewpoint (R = amino acid side chain)

Kurt Wüthrich was the first person to solve a protein structure by NMR in 1984. ⁵  He used the same two dimensional NMR techniques which had been developed previously for small organic molecules by fellow Swiss scientist, Richard Ernst, ³  who was awarded the Nobel prize for chemistry in 1992 for his work in this area. (In 2002, Wüthrich was also awarded the Nobel prize in chemistry for his achievements in developing NMR for the study of proteins.)  

Wüthrich first assigned each resonance in the ¹H-nmr spectrum of the protein BPTI to a specific hydrogen nucleus, using experiments such as COSY, which established 'connections' between protons made through covalent bonds. He then determined the overall three dimensional structure of the protein by making use of correlations observed in a NOESY experiment. Because the nuclear Overhauser effect probes 'connections through space', rather than through bonds, it identifies protons which are brought into close proximity to one another by virtue of the folding of the protein, even though these protons may be quite distant in the linear sequence (see Fig 5). Given sufficient nOe-derived 'distance constraints', it then became possible to reconstruct the three dimensional shape of the BPTI protein. This reconstruction generally requires the use of computers, which convert the large number of nOe-derived distance restraints into energy terms, and then minimise the energy of the system as a whole. Such an approach typically results in an ensemble of structures, depending on which initial conditions are used by the computer algorithm. These structures overlap in highly ordered regions of the interior of the BPTI protein, but there is less convergence in more disordered regions on the surface. 

Protein NMR spectroscopy has evolved rapidly since Wüthrich's first experiments more than two decades ago. Nowadays, it is common practice to study proteins which have been isotopically-labelled,* subjecting them to a variety of three dimensional multinuclear NMR experiments.  

*Proteins labelled by ¹³C and ¹⁵N are normally produced by recombinant expression of the relevant gene in a host, such as E. coli, which is grown on a minimal medium, enriched with the desired isotopes (typically, supplied as [U-¹³C]-glucose and ¹⁵NH₄Cl).

The modern strategy for solving the structure of a protein by NMR begins with the NH protons in the peptide bond (Fig 5). For a reasonable sized protein many NH resonances will be crowded into a narrow region of the one dimensional ¹H-nmr spectrum between 6-10 ppm, and there will inevitably be a high degree of overlap. However, the probability of overlap is greatly reduced by the introduction of not just a second, but also a third dimension.    

Fig 6 a 3D-HNCO spectrum, which represents each of the H, N, and C atoms in a peptide linkage as an elipsoid in three dimensional space © Reinhard Bunkel/sciencesoft.net

In the case of the three dimens-ional NMR 'HNCO' experiment these two extra dimensions correspond to the chemical shift of the nitrogen atom to which this hydrogen is attached (labelled by ¹⁵N), and to that of the adjacent C=O group in the peptide bond (labelled by ¹³C). As well as serving to reduce the probability of overlap for NH protons, this experiment also 'connects together' all the proton, nitrogen and carbon resonances in a peptide bond. Thus, each of the various peptide bonds in a protein appears individually as a small sphere in the HNCO experiment shown in Fig 6. The limits of this experiment are set by a cube which is defined by three orthogonal axes corresponding to the chemical shifts of mutually-coupled ¹H, ¹⁵N and ¹³C nuclei. Many other three dimensional NMR experiments have been developed for the study of proteins over the past two decades. However, only a few of these, such as HNCA and HN(CO)CA, which when used together with HCNO allow the assignment of all the carbon, hydrogen and nitrogen resonances in the backbone of a protein, continue to find routine use.  

References

1. G. Brown, Educ. Chem., 2008, 45(4), 108.
2. J. Jeener, Ampere International Summer School, Basko Polje, Yugoslavia, 1971.
3. R. R. Ernst, G. Bodenhausen and A. Wokaun, Principles of nuclear magnetic resonance in one and two dimensions. Oxford: Clarendon, 1987.
4. T. D. W. Claridge, High-resolution NMR techniques in organic chemistry. Tetrahedron organic chemistry series, Vol 19. Amsterdam: Elsevier, 2004.
5. K. Wüthrich, Angew. Chem. Int. Edn, 2003, 42, 3340.









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Supramolecular “containers”: self-assembly and functionalization of thiacalix[4]arenes for recognition of amino- and dicarboxylic acids

RSC Adv., 2014,4, 3556-3565

DOI: 10.1039/C3RA44052D

http://pubs.rsc.org/en/content/articlelanding/2013/ra/c3ra44052d#!divAbstract

New p-tert-butylthiacalix[4]arenes containing amide, tertiary amine and ammonium fragments incone conformation were synthesized and characterized. The interaction of the p-tert-butylthiacalix[4]arenes with amino-, dicarboxylic acids and EDTA was studied by electron spectroscopy. The ability of the synthesized thiacalix[4]arenes to form supermolecules and supramolecular associates with guests was shown by dynamic light scattering. The formation of commutative and cascade supramolecular systems based on amphiphilic macrocycles was studied by UV spectroscopy and dynamic light scattering. It was shown that thiacalix[4]arene containing quaternary ammonium fragments with three methyl groups at the nitrogen form associates – “containers” containing glutamic acid as a guest.