7H-Pyrrolo[2,3-d]pyriMidin-4-aMine, N-Methyl-N-[(3R,4R)-4-Methyl-1-(phenylMethyl)-3-piperidinyl]-7-[(4-Met hylphenyl)sulfonyl]-

Uses

A useful intermediate for the formal asymmetric synthesis of (+)-Tofacitinib. An impurity of Tofacitinib(C781351).

Synthesis

(3R,4R)-1-benzyl-4-methyl-3-methylamino-piperidine (4.3 g, 19.7 mmol, 1.0 eq.) was dissolved in 180 mL of water, followed by the addition of 4-chloro-7-toluenesulfonyl-7H-pyrrolo[2,3-D]pyrimidine (12.3 g, 39.2 mmol, 2.0 eq.) and potassium carbonate (16.6 g, 119 mmol. 6.0 eq.). The reaction mixture was stirred at 100 °C for 16 h and then cooled to room temperature. After completion of the reaction, the reaction was extracted three times with ethyl acetate (500 mL), the organic phases were combined and washed sequentially with water and brine. The organic layer was dried with anhydrous sodium sulfate and concentrated under reduced pressure to remove the solvent. The crude product was purified by column chromatography (eluent: ethyl acetate/petroleum ether=1:1) to afford N-((3R,4R)-1-benzyl-4-methylpiperidin-3-yl)-N-methyl-7-toluenesulfonyl-7H-pyrrolo[2,3-d]pyrimidin-4-amine (8.6 g, 90% yield) as a pale yellow solid.

References

[1] Patent: CN103896946, 2018, B. Location in patent: Paragraph 0084; 0085; 0086
[2] Journal of Medicinal Chemistry, 2008, vol. 51, # 24, p. 8012 - 8018