Carbon tetrabromide → 6-(Bromomethyl)-2-methyl-1,3-benzoxazole

To a suspension of (2-methyl-1,3-benzoxazol-6-yl)methanol (66.5 mg, 0.408 mmol) in toluene (1 mL) were added carbon tetrabromide (135 mg, 0.408 mmol) and triphenylphosphine (106 mg, 0.408 mmol) and the mixture was stirred at room temperature for 30 min. The reaction mixture was directly applied to silica gel, and concentrated to dryness to give 6-(bromomethyl)-2-methyl-1,3-benzoxazole as an oil. To the obtained oil (92.0 mg, 0.408 mmol) were added DMF (4 mL), N-[1-(5-hydroxy-1-benzofuran-2-yl)ethyl]acetamide (30.0 mg, 0.136 mmol) obtained in Reference Example 38 and potassium carbonate (37.8 mg, 0.274 mmol), and the mixture was stirred at 50° C. for 2 hr. The reaction mixture was directly purified by basic silica gel column chromatography (hexane:ethyl acetate-4:1 to 3:7), and the solvent was evaporated. The residue was triturated with a small amount of ethyl acetate and diethyl ether to give the title compound (17.8 mg, yield 36%) as a white solid.