To a solution of 3-[4-(7H-pyrrolo[2,3-d]pyrimidin-4-yl)-1H-pyrazol-1-yl]heptanenitrile (0.363 g, 1.23 mmol) in isopropyl alcohol (8.0 mL) was added phosphoric acid (0.133 g, 1.36 mmol) in 1.0 mL isopropyl alcohol at 60° C. The mixture was heated at 60° C. for 1 hour, then cooled to room temperature. The precipitate was filtered off and air dried, rinsed with ethyl ether, and then air dried further to provide the desired phosphoric acid salt (418 mg, 86.5%). 1H NMR (DMSO-d6, 400 MHz) δ 12.10 (1H, s), 8.78 (1H, s), 8.66 (1H, s), 8.36 (1H, s), 7.58 (1H, m), 6.97 (1H, m), 4.71 (1H, m), 3.18 (1H, m), 3.17 (1H, m), 1.93 (1H, m), 1.82 (1H, m), 1.21 (3H, m), 0.95 (1H, m), 0.78 (3H, t, J=7.2 Hz) ppm.
