To a dichloromethane (1 ml) solution of the [6-[(4-chlorophenylsulfonyl)(2,5-difluorophenyl)methyl]pyridin-3-yl]methylamine (41 mg, 0.10 mmol) obtained in Example 63, (E)-3-(pyridin-4-yl)acrylic acid (15 mg, 0.10 mmol), benzotriazol-1-ol (14 mg, 0.10 mmol) and N-methylmorpholine (0.011 ml, 0.10 mmol) was added 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride (19 mg, 0.10 mmol) at 0° C. The resulting mixture was stirred at room temperature for 19 hours. The reaction mixture was washed with a saturated aqueous solution of sodium bicarbonate. The organic layer was dried over anhydrous sodium sulfate and filtered. The filtrate was concentrated under reduced pressure. The residue thus obtained was subjected to flash silica gel chromatography. The fraction obtained from the ethyl acetate eluate was concentrated under reduced pressure. The solid thus obtained was washed with diethyl ether and collected by filtration to give the title compound (35 mg, 0.065 mmol, 65%) as a white solid.
