To a stirred and cooled (0° C.) solution of (2RS,5SR)-[5-(4-fluoro-phenyl)-1-(toluene-4-sulfonyl)-pyrrolidin-2-yl]-methanol in THF (10 ml) was added sodium hydride (147 mg, 3.66 mmol, 60%) and the reaction mixture was stirred at room temperature for 1 h. Subsequently methyl iodide (0.34 ml, 5.5 mmol) was added at 0° C. and stirring was continued for 3 h at room temperature. Aqueous work-up and crystallization from ethyl acetate/hexane yielded the title compound as a white solid (0.53 g, yield 79%), m.p. 152° C. and MS: m/e=364.3 (M+H+).
