To a solution of 5-(2-chloropyridin-3-yl)-1H-pyrrole-3-carbaldehyde (110 mg) in tetrahydrofuran (11 mL) was added sodium hydride (60% in oil, 64 mg) at room temperature and the mixture was stirred for 10 min. 3-Cyanobenzenesulfonyl chloride (215 mg) was added and the mixture was further stirred for 15 min. The reaction mixture was diluted with saturated aqueous sodium hydrogen carbonate solution, and extracted with ethyl acetate. The obtained extract was washed with saturated brine, dried over anhydrous magnesium sulfate, and concentrated under reduced pressure. The residue was crystallized from diethyl ether to give the title compound as colorless crystals (yield 150 mg, 76%).
