| abstract |
The present invention provides a method for reducing a 7H-pyrrolo [2,3-d] pyrimidine derivative that is useful as a janus kinase inhibitor (JAK); an intermediate of the 7H-pyrrolo [2,3-d] pyrimidine derivative; and a method to produce the intermediary; The present invention provides a method of producing 3 - [(3S, 4R) -3-methyl-6- (7 H -pyrrolo [2,3-d] pyrimidin-4-yl) -1,6-diazaspiro [3.4] octan -1-yl] -3- oxopropanenitrile, which uses a salt of an organic acid and benzyl acid (3S, 4R) - 3-methyl-1,6-diazaspiro [3.4] octane-1-carboxylic acid. |