To a solution of N-piperazinyl-p-fluorobenzamide hydrobromide (300 mg), cinnamic acid (161 mg), and 1-hydroxybenzotriazole (173 mg) in N,N-dimethylformamide (6 ml) was added N-ethyl-N′-(3-dimethylaminopropyl)carbodiimide hydrochloride (246 mg) and triethylamine (0.28 ml) at 5° C. The mixture was stirred at 5° C. for 1 hour, and then poured into ethyl acetate and brine. The organic layer was separated, dried over magnesium sulfate, and concentrated. The residue was crystallized from ethyl acetate-diethyl ether to give N-(4-cinnamoyl-1-piperazinyl)-p-fluorobenzamide (0.14 g).
