To a stirred mixture of trans-4-[8-amino-1-(4-phenoxy-phenyl)-imidazo[1,5-a]pyrazin-3-yl]-cyclohexanecarboxylic acid methyl ester (150.00 mg, 0.33 mmol) in EtOH (3.00 mL) was added solution of sodium hydroxide (67.8 mg, 1.69 mmol) in H2O (0.500 mL) at 0° C. Then the mixture was stirred at rt. overnight. The solvent was then removed under reduced pressure to give a residue which was dissolved in H2O (3 ml). The solution was acidified to pH 1 by formic acid. The product precipitated out and was collected by filtration and dried on high vacuum pump. 1H NMR (400 MHz, MeOD) δ 1.59-1.88 (m, 4H), 2.03-2.21 (m, 4H), 2.35-2.46 (m, 1H), 3.09-3.20 (m, 1H), 6.99 (d, J=5.1 Hz, 1H), 7.04-7.20 (m, 5H), 7.35-7.45 (m, 2H), 7.53-7.63 (m, 3H). MS (ES+): m/z 428.97 (MH+). HPLC: tR=2.25 min (OpenLynx, polar—5 min).
