In two different preparations, 4-(3-trifluoromethylphenyl)-1,2,3,6-tetrahydropyridine is reacted, in the presence of triethylamine, with 2-(2-bromoethyl)naphthalene (PREPARATION A) and respectively with 2-(2-chloroethyl)naphthalene (PREPARATION B) in ethanol under reflux for 20 hours. The reaction mixtures of the two preparations were concentrated, the residue was taken up with ethyl ether and the ether solution, which was filtered and washed with water, was dried and evaporated. The residue was taken up with a solution of gaseous hydrochloric acid in isopropanol to give 1-[2-(2-naphthyl)ethyl]-4-(3-trifluoromethylphenyl)-1,2,3,6-tetrahydropyridine hydrochloride, which was crystallized from ethanol.
