Under ice cooling, ethyl chlorocarbonate (96 μl) was added to a suspension of sodium fluoroacetate (100 mg) in dimethylformamide (5 ml) and the resultant mixture was stirred for 20 min. Next, a solution of 1-[1-(4-fluorophenethyl)piperidin-4-yl]-6-aminomethylindole (150 mg) obtainedinExample 322-3) indimethylformamide (5 ml) was added thereto and the resultant mixture was stirred at room temperature for 2 hr. Then a saturated aqueous solution of sodium bicarbonate and ethyl acetate were added to the reaction mixtures. The organic layer was separated, washed with brine, dried over anhydrous magnesium sulfate and concentrated under reduced pressure. The resulting residue was purified by silica gel column chromatography (hexane/ethyl acetate system) to give the title compound (100 mg) as a white powder (yield: 57%).
