The [6-[(4-chlorophenylsulfonyl)(2,5-difluorophenyl)methyl]pyridin-3-yl]methylamine (30 mg, 0.073 mmol) obtained in Example 63, 3-pyridylacetic acid hydrochloride (16 mg, 0.092 mmol), 4-(dimethylamino)pyridine (5 mg, 0.04 mmol) and triethylamine (0.025 ml, 0.18 mmol) were dissolved in dichloromethane (5 ml). To the resulting solution was added 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride (17 mg, 0.089 mmol) at room temperature. The resulting mixture was stirred at room temperature for 14 hours. To the reaction mixture was added a saturated aqueous solution (0.1 ml) of sodium bicarbonate. The residue obtained by concentrating the reaction mixture under reduced pressure was subjected to flash silica gel chromatography. The fraction obtained from the dichloromethane:methanol=30:1 elute was concentrated under reduced pressure to afford a white solid. The resulting solid was washed with ether to give the title compound (35 mg, 0.066 mmol, 90%) as a white powder.
