To a solution of 1.018 g (2.95 mM) of 3-hexadecylthio-2-methoxypropylamine IV a2 in 15 ml of dichloromethane and 0.534 ml (3.83 mM) of triethylamine is added 0.563 mg (3.24 mM) of 3-chloropropanesulfonyl chloride with ice-cooling and the mixture is stirred at 0° C. for 3 hours. After the solvent is evaporated, the residue is purified by the column chromatography on silica gel with a n-hexane-ethyl acetate (4:1) mixture as an eluent. The product is recrystallized from chloroform-n-hexane to give 1.275 g (2.62 mM) of 3-(3-chloropropylsulfonylamino)-1-hexadecylthio-2-methoxypropane III a2 as a colorless powder in 89% yield.
