A mixture of 3′-fluoro-4′-{[4-(4-{1-[1-(1-hydroxyethyl)cyclobutyl]ethoxy}cyclohexyl)-5-oxo-7-propyl-4,5-dihydro[1,2,4]triazolo[1,5-a]pyrimidin-6-yl]methyl}biphenyl-2-carbonitrile (13 g), Dess-Martin periodinane (10 g) and acetonitrile (130 mL) was stirred at room temperature for 30 min. Saturated aqueous sodium hydrogen carbonate solution and 1 M aqueous sodium thiosulfate solution were added to the reaction mixture, and the mixture was extracted with ethyl acetate. The organic layer was washed with saturated brine, and dried over anhydrous magnesium sulfate. The solvent was evaporated under reduced pressure, and the residue was purified by silica gel column chromatography to give the title compound as a colorless solid (11 g, 88%).
