A solution of 7-bromomethylbenzofuran-3(2H)-one (0.573 g, 2.52 mmol) in methylene chloride (20 mL) was added with sodium acetate (0.412 g, 5.03 mmol) and 1-tert-butoxycarbonylpiperazine (0.721 g, 3.87 mmol), and the mixture was stirred at room temperature for 6 hours. The organic layer was washed with water and saturated brine, and then dried over anhydrous magnesium sulfate, and then the solvent was evaporated under reduced pressure. The resulting residue was purified by silica gel column chromatography (hexane/ethyl acetate) to obtain tert-butyl 4-[(3-oxo-2,3-dihydrobenzofuran-7-yl)methyl]piperazine-1-carboxylate (0.391 g, 46%).
