1.8 g of the Z-3-[4-dimethylaminomethyl-3-(3-methoxy-phenyl)-cyclohex-2-enylidenemethyl]-benzoic acid base prepared according to example 4 were dissolved in 50 ml analytical grade dimethylformamide, and 2 g DCC and 1.1 g hydroxysuccinimide were added at 0° C. to 15° C. The mixture was stirred at 0° C. for one hour and 2 ml diethylamine were then added dropwise at this temperature. The mixture was stirred at 0° C. for an additional hour and then at room temperature for four days. The reaction mixture was poured on to 300 ml saturated sodium chloride solution and the mixture was then extracted 3 times with 250 ml ethyl acetate each time. The organic phases were washed with 50 ml saturated sodium chloride solution and then dried over magnesium sulfate. The solvent was removed in vacuo. The residue was chromatographed on silica gel with ethyl acetate/methanol=6/5. 0.87 g Z-3-[4-dimethylaminomethyl-3-(3-methoxy-phenyl)-cyclohex-2-enylidenemethyl]-N,N-diethyl-benzamide base was obtained in this way in the form of an orange-yellow oil. To liberate the hydrochloride, the oil was dissolved in 5 ml acetone, and an equimolar amount of trimethylchlorosilane and water was added. 0.52 g (22.1% of theory) of the title compound 34 was obtained in this way in the form of white crystals.
