A solution of triphosgene (190 mg, 0.640 mmol) in dichloromethane (6.0 ml) was stirred at room temperature under a nitrogen atmosphere. A solution of 2-(1-adamantyl)-N-methylethylamine (Intermediate No. 3-1, 330 mg, 1.71 mmol) and diisopropylethylamine (0.357 ml, 2.05 mmol) in dichloromethane (6.0 ml) was added dropwise thereto over 17 minutes. After eight minutes, a solution of N-methyl-3-(4-pyridyl)propylamine (Intermediate No. 3-3, 264 mg, 1.78 mmol) and diisopropylethylamine (0.357 ml, 2.05 mmol) in dichloromethane (5.1 ml) was added to the mixture all at once, and the whole was stirred for 20 hours. The reaction mixture was diluted with diethyl ether (40 ml), the whole was washed with a saturated aqueous sodium hydrogencarbonate solution (40 ml) twice and a saturated aqueous sodium chloride solution (40 ml) successively, and the organic layer was dried over magnesium sulfate. The solvent was evaporated under reduced pressure, and the residue was purified by silica gel column chromatography to give the target compound (335 mg, 54%).
