To a solution of 400 mg of cis-N-benzyl-N-(4-phenylcyclohexyl)amine in 20 ml of dichloromethane were added 2 ml of pyridine and then a solution of 310 mg of 2,6-diisopropylphenylisocyanate in 5 ml of dichloromethane dropwise. The mixture was stirred at room temperature, poured into diluted hydrochloric acid and extracted with ethyl acetate. The extract was washed with water, aqueous sodium hydrogencarbonate solution and saturated brine and then dried over magnesium sulfate. The solvent was distilled away in vacuo to give crude crystals. The crystals were recrystallized from the mixture of ethyl acetate and hexane to give 460 mg of cis-N-(2,6-diisopropylphenyl)-N'-benzyl-N'-(4-phenylcyclohexyl)urea, melting at 153°-154° C.
