Methylmagnesium bromide (1M THF solution, 4.75 ml) was added to a mixture of ethyl 3-[3-methoxy-4-(2-methyl-1,3-oxazol-5-yl)phenyl]-8-[4-(trifluoromethyl)phenoxy]-5,6,7,8-tetrahydro[1,2,4]triazolo[4,3-a]pyridine-8-carboxylate (515 mg) in THF (7 mL) under ice-cooling, and the mixture was stirred for 1 hr. Saturated aqueous ammonium chloride solution was added, and the mixture was extracted with ethyl acetate. The extract was washed with saturated aqueous sodium hydrogen carbonate solution and saturated brine, and dried over anhydrous sodium sulfate, and the solvent was evaporated under reduced pressure. The residue was purified by basic silica gel column chromatography (NH, ethyl acetate/hexane) to give the title compound (250 mg).
