A mixture of 4.5 g of 1-(6-benzyloxy-2-naphthyl)-2-(2-chloroethoxy)ethanol, 1 g of potassium iodide, 10 ml of a 50% aqueous dimethylamine solution and 20 ml of ethanol was refluxed for 3 hours. To the reaction mixture was added 10 ml of a 50% aqueous dimethylamine solution. The resulting mixture was further refluxed for 6 hours. The reaction mixture was cooled and concentrated to about a half volume under reduced pressure. To the concentrate were added 100 ml of ethyl acetate and 100 ml of water. The mixture was adjusted to pH 10.5 with potassium carbonate. The organic layer was separated, washed with water and a saturated aqueous sodium chloride solution in this order, and dried over anhydrous magnesium sulfate. The solvent was removed by distillation under reduced pressure. To the residue thus obtained was added 30 ml of diethyl ether. The resulting crystals were collected by filtration and dried to obtain 3.9 g of 1-(6-benzyloxy-2-naphthyl)-2-[2-(N,N-dimethylamino)ethoxy]-ethanol (compound No. 284).
