A mixture of 4-bromo-2,2-bis(fluoromethyl)-6-trifluoromethyl-2H-1-benzopyran (1.73 g), 2-cyanoethylamine (1.44 g), potassium iodide (0.86 g), triphenylphosphine (26 mg), palladium acetate (11 mg) and N,N-dimethylacetamide (10 ml) was stirred under a CO atmosphere at 100° C. for 3 hours. To the reaction mixture, 2 N HCl was added and the precipitating crystals were recovered by filtration. To the recovered crystals, ethyl acetate was added and the insoluble matter was filtered off; the filtrate was washed with a saturated aqueous solution of sodium thiosulfate and a saturated aqueous solution of sodium chloride, dried with anhydrous sodium sulfate and concentrated under reduced pressure; the resulting residue was recrystallized with an ethanol/water mixed solvent, thereby giving N-(2-cyanoethyl)-2,2-bis(fluoromethyl)-6-trifluoromethyl-2H-1-benzopyran-4-carboxamide (1.46 g) having a melting point of 129-131° C.
