A mixture of 6.16 g of 1-chloro-4-phenyl-4-phenylsulfonylbutane, 4.25 g of 4-(4-pyridylmethyl)piperazine, 4.24 g of sodium carbonate and 80 ml of toluene was refluxed with stirring for 72 hours. After cooling, water was added to the reaction mixture and the toluene layer was separated. The eoluene layer was extracted with a 10% aqueous hydrochloric acid solution and neutralized with potassium carbonate and then extracted with ethyl acetate. After drying over potassium carbonate, to the extract was added 7.0 g of maleic acid. The resulting maleate was purified with 2-propanol to give 3 g of 1-(4-phenyl-4-phenylsulfonylbutyl)-4-(4-pyridylmethyl)piperazine trimaleate, melting at 144°-146° C with decomposition.
