Triethylamine (0.96 ml) and octadecyl isocyanate (2.2 ml) were added to a solution of 6-(hydroxymethyl)-N-(2-piperidinoethyl)-3-cyclohexene-1-carboxamide (1.65 g) in methylene chloride (22 ml). After being stirred for 15 hours at room temperature, triethylamine (0.96 ml) and octadecyl isocyanate (2.2 ml) were further added to the reaction mixture and stirred for 5 hours at room temperature. The insoluble matters were filtrated out under a vacuum and washed with chloroform. The filtrate and washings were combined together and the mixture was washed with saturated sodium hydrogencarbonate aqueous solution and saturated brine successively, dried over sodium sulfate anhydride, and concentrated. The residue was purified by silica gel column chromatography (silica gel 100 g, chloroform:methanol=30:1-10:1), thereby yielding the entitled compound (2.59 g) as white solid.
