0.6 ml of a 4N solution of hydrogen chloride in dioxane was added to a solution of 0.650 g of 2-(2-{2-[2-(4-ethylphenyl)ethyl]phenoxy}ethyl)-1-methylpiperidine [prepared as described in step (a) above] in a suitable amount of ethyl acetate, and the resulting solution was concentrated by distillation under reduced pressure. The resulting oily residue was dissolved in ethyl acetate, and a small amount of diethyl ether was added to the solution, which was then allowed to stand at room temperature. The crystals which precipitated were collected by filtration and dried in vacuo, to give 0.590 g (yield 82%) of the title compound as colorless crystals, melting at 101°-103° C.
