A solution of 17.5 g (60 mmole) of 1-(diphenylmethoxy)-2-bromoethane in 50 cm3 of dimethylformamide was added to a mixture of 10.6 g (60 mmole) of 3-(3-methoxyphenyl)pyrrolidine [prepared according to A. Ebnother and K. Hasspacher, Swiss Patent No. 526 536], 16.6 g (120 mmole) of potassium carbonate, 300 cm3 of dimethylformamide and a few potassium iodide crystals. The mixture was heated at 80° C. for 13 hours, and concentrated to dryness under reduced pressure after it returned to room temperature. The residue was taken up with 500 cm3 of 1N hydrochloric acid and extracted with ether. The aqueous acid phase was separated, basified with 10N sodium hydroxide solution, and extracted with methylene chloride. The organic solution was dried on sodium sulfate. The evaporation of the solvent provided an oily residue. Purification by silica gel filtration (eluent, hexane-ethyl acetate, 1/1) yielded 10 g of 1-[2-(diphenylmethoxy) ethyl]-3-(3-methoxyphenyl)pyrrolidine, which was dissolved in 100 cm3 of ether. To this solution was added a solution of 2.55 g (28.3 mmole) of oxalic acid in 30 cm3 of acetone. The oxalate precipitate was filtered and recrystallized from acetone.
