Benzoic Acid → 3-(4-(aminomethyl)-1-(5-methyl-7H-pyrrolo[2,3-d]pyrimidin-4-yl)piperidine-4-carboxamido)phenyl dimethylcarbamate benzoate

To a flask was added 3-(4-(aminomethyl)-1-(5-methyl-7H-pyrrolo[2,3-d]pyrimidin-4-yl)piperidine-4-carboxamido)phenyl dimethylcarbamate freebase (99.9 mg, 0.221 mmol, 1 eq) and acetonitrile (2.3 mL), followed by the addition of benzoic acid (33.1 mg, 0.271 mmol, 1.23 equiv). After the reaction mixture was stirred at room temperature for 30 minutes, methanol (0.5 mL) was added. The slurry was heated to 65° C. and stirred for 30 minutes, then methanol was evaporated. The reaction mixture was cooled to room temperature and stirred for 2 hours. The solid was collected by filtration, washed with MTBE (1 mL) and dried at 40-45° C. under vacuum overnight to afford 3-(4-(aminomethyl)-1-(5-methyl-7H-pyrrolo[2,3-d]pyrimidin-4-yl)piperidine-4-carboxamido)phenyl dimethylcarbamate benzoate (104.1 mg, 82.1%) as an off-white solid.