| abstract |
The present invention relates to methods and intermediates for the preparation of compounds useful as inhibitors of Janus kinase (JAK). The invention also relates to (R) -2- (2- (1H-pyrrolo [2,3-b] pyridin-3-yl) pyrimidin-4-ylamino) -2-methylbutanoic acid (Form E) The solid phase form of 4a) is provided. In some embodiments, solid phase Form E has 7.1 ± 0.2, 8.2 ± 0.2, 23.9 ± 0.2, and 24.8 ± 0. It is characterized by one or more peaks corresponding to 2 (unit: measured in degrees) 2θ values. |