To a solution of 4′-({4-[4-(1,1-dimethyl-2-oxoethoxy)phenyl]-5-oxo-7-propyl-4,5-dihydro[1,2,4]triazolo[1,5-a]pyrimidin-6-yl}methyl)biphenyl-2-carbonitrile (0.97 g) in tetrahydrofuran (10 mL) was added dropwise methylmagnesium bromide (1 M tetrahydrofuran solution, 0.91 mL) at 0° C., and the mixture was stirred for 3 hr. Ethyl acetate and then saturated aqueous ammonium chloride solution were added. The mixture was extracted with ethyl acetate, and the organic layer was washed with saturated brine, dried over anhydrous magnesium sulfate, and concentrated. The residue was purified by silica gel column chromatography to give the title compound as a pale-yellow amorphous solid (0.72 g, 72%).
