To a mixture of 2,2,2-trifluoro-N-(3-oxo-1-{4-[9-phenyl-3-(2-pyrimidinyl)[1,2,4]triazolo[3,4-f]-1,6-naphthyridin-8-yl]phenyl}cyclobutyl)acetamide (4-2) (25 mg, 0.043 mmol) in CH2Cl2 (1 mL) and MeOH (1 mL) was added NaBH4 (2.0 mg, 0.052 mmol) at −78° C., and the mixture was stirred at −78° C. for 1 hour. The mixture was quenched with sat. NH4Cl, extracted with CHCl3, washed with brine, dried (MgSO4), filtered, and concentrated under reduced pressure to give 2,2,2-trifluoro-N-(3-hydroxy-1-{-4-[9-phenyl-3-(2-pyrimidinyl)[1,2,4]triazolo[3,4-f]-1,6-naphthyridin-8-yl]phenyl}cyclobutyl)acetamide (4-3). MS (M+H)+: observed=581, calculated=581.
