240 mg of 2-thiophenecarboxylic acid, 390 mg of N,N'-dicyclohexylcarbodiimide and 275 mg of 1-hydroxybenzotriazole were added to a solution of 485 mg of 4-(4-piperidinomethyl-2-pyridyloxy)-cis-2-butenylamine in 10 ml of dry dimethylformamide, and the resulting mixture was stirred at room temperature for 17 hours. At the end of this time, the reaction mixture was mixed with ethyl acetate, and the urea which precipitated was removed by filtration. The filtrate was diluted with water and extracted with ethyl acetate. The extract was washed with a saturated aqueous solution of sodium hydrogencarbonate and then with a saturated aqueous solution of sodium chloride, after which it was dried over anhydrous magnesium sulfate. The solvent was then removed by distillation under reduced pressure, and the residue was purified by column chromatography through silica gel, using a 1:19 by volume mixture of methanol and methylene chloride as the eluent, to give 499 mg (yield 73%) of the title compound as an oil.
