A mixture of 818 mg (1.82 mmol) of 4-benzyloxy-3-(N-tert-butoxycarbonyl-N-methylsulfonylamino)-1-((2S)-2,3-epoxypropoxy)benzene and 450 mg (1.82 mmol) of ethyl trans-4-[4-(benzylamino)cyclohexyl]benzoate in the form of a base is heated under reflux in 15 ml of absolute ethanol for 16 hours. The mixture is cooled, 3 ml of an ethanol solution saturated with hydrochloric acid are added thereto and the medium is heated at 50° C. for 6 hours. The solvent is evaporated and the medium is taken up in a mixture of 50 ml of a saturated sodium bicarbonate solution and 50 ml of ethyl acetate. The organic phase is washed with a saturated aqueous NaCl solution. The organic phase is dried, filtered and the solvent is evaporated under reduced pressure. The crude product is purified by chromatography on a silica gel column, eluting with a methylene chloride/methanol/NH4OH (95/5/0.5) mixture. The title compound is obtained in the form of a white solid. [M+H+]=687.
