A mixture of 5.85 g (0.02 mole) of 4-[bis(4-fluorophenyl)methyl]piperidine, 3.76 g (0.02 mole) of 2-(3-chloropropoxy)-1-fluorobenzene, and sodium carbonate (4.80 g, 0.045 mole) in 300 ml of 1-butanol containing 0.3 g of potassium iodide was heated overnight at gentle reflux. The reaction mixture was stripped to dryness and the resulting oil partitioned between chloroform-5% sodium hydroxide and then between chloroform-water. Removal of chloroform gave an oil which was converted to the oxalate salt. The salt was recrystallized from methanol-diethyl ether. The salt was subsequently triturated with isopropanol, and was dried overnight at 80° C. to give 5.82 g (55%) of product, m.p. 182°-183° C.
