Potassium tert-butoxide → 2-(Methoxymethyl)-5-[3-[3-(trifluoromethoxy)phenyl]-1-benzofuran-5-yl]-1,3,4-oxadiazole

A solution of 2-(chloromethyl)-5-[3-[3-(trifluoromethoxy)phenyl]-1-benzofuran-5-yl]-1,3,4-oxadiazole (0.30 g, 0.76 mmol) and potassium tert-butoxide (85%, 0.12 g, 0.91 mmol) in methanol (5 mL) was stirred overnight at room temperature. Potassium tert-butoxide (85%, 0.03 g, 0.23 mmol) was added to the reaction mixture, and the resulting mixture was stirred at 50° C. overnight. The reaction mixture was concentrated under reduced pressure, saturated aqueous ammonium chloride solution was added to the residue, and the mixture was extracted with ethyl acetate. The organic layer was washed with saturated brine, dried over anhydrous sodium sulfate, and concentrated under reduced pressure. The residue was purified by silica gel column chromatography (hexane/ethyl acetate=3/1) and recrystallized from hexane/ethyl acetate to give the title compound (0.20 g, yield 67%) as colorless crystals.