Diethyl Ether → N-(3-octadecanoyloxypropyl)-N,N-dimethyloctadecanaminium bromide

To a solution of 0.2 mole octadecanoylchloride in 400 ml ethyl ether was added a solution of 32 g (0.31 mole) 3-dimethylamino-1-propanol in 50 ml ethyl ether. After stirring about 2 hours, the reaction mixture was filtered and the solid recrystallized from ethyl acetate. It was converted to the free base, 3-dimethylaminopropyl octadecanoate, with sodium hydroxide and recrystallized from acetonitrile. A mixture of 18.3 g (0.049 mole) of this amine and 16.2 g (0.049 mole) of 1-bromooctadecane was heated in an oven at 100° C. for 7 hours. After washing with ethyl ether to remove any unreacted material the product was recrystallized from ethyl alcohol and washed with ethyl acetate.