cis-1-(3-Acetoxymethylpiperidin-4-yl)indoline (280 mg) was dissolved in dimethylformamide (4 ml) and methanol (1 ml). To the resultant solution were added triethylamine (222 mg) and 4-fluorophenethyl bromide (285 mg) followed by stirring at 50° C. for 2 hr. Then the reaction mixture was cooled and water (50 ml) was added thereto. After extracting with ether (50 ml) twice, the organic phase was washed with water (20 ml) twice and a 2 N aqueous solution (50 ml) of sodium hydroxide once and dried over anhydrous magnesium sulfate. Then the solvent was evaporated under reduced pressure and the residue was purified by silica gel column chromatography (hexane/ethyl acetate system) to give the title compound (100 mg) as a colorless oil (yield: 28%).
