600 mg (2.76 mmol) of 3-oxo-N-(3-phenyl-2-propene-1-yl)butyramide, 362 mg (2.76 mmol) of 4-cyanobenzaldehyde and 23.5 mg (0.276 mmol) of piperidine were heated under reflux in the presence of a catalytic amount of p-toluenesulfonic acid in 30 ml of benzene for 6 hours while water was removed. Benzene was evaporated under reduced pressure. Ethyl acetate was added to the reaction mixture. After washing with 1 N hydrochloric acid and then with a saturated aqueous sodium hydrogencarbonate solution, the organic layer was dried over anhydrous sodium sulfate and then concentrated under reduced pressure. The residue was purified by the silica gel chromatography (hexane/ethyl acetate=5/1) to obtain the title compound.
