To a solution of 35.7 mg (0.08 mmol) rac-2-methoxy-N-(3-phenyl-piperidin-3-yl)-4,6-bis-trifluoromethyl-benzamide in methanol were added 28 ul (0.48 mmol) acetic acid, 59 ul (0.8 mmol) acetone and finally 30 mg (0.4 mmol) sodium cyanoborohydride. The mixture was stirred at room temperature for 4 hours. The solvent was removed in vacuo. The residue was taken in ethyl acetate. The mixture was washed once with a 1N NaOH solution, once with water and once with brine. The aqueous layer was extracted once with ethyl acetate. The combined organic layers were dried over sodium sulfate, filtered and concentrated in vacuo. The crude product was purified on silica gel (Eluent: Heptane/ethyl acetate 0 to 100%) to provide 33 mg (85%) of the title compound as a white foam. MS (m/e): 489.4 (M+H).
