Methyl 2-{[4-(2-oxo-2-{[4-(trifluoromethyl)benzyl]amino}ethyl)phenoxy]methyl}-benzoate (71 mg, 0.155 mmol) in THF (1.5 ml) was cooled in an ice-bath. Lithium hydroxide (7.5 mg, 0.310 mmol) in water (1.5 ml) was dropped in. The cooling-bath was then removed and the mixture was stirred overnight. HPLC showed that the reaction was not complete. More lithium hydroxide (0.2M, 0.5 ml) was added. The reaction mixture was stirred for 4 days more. It was then evaporated in vacuum to remove THF. The residue was acidified with 1% hydrochloric acid, pH=3-4, and then extracted with ethyl acetate. The organic phase was dried with magnesium sulphate and evaporated. Chromatography of the residue on a column (ISOLUTE® SI, 2 g/6 ml) using DCM, MeOH/DCM (0.5:99.5, then 1:99, and then 2:98) as eluant gave 39 mg white solid product, yield 57%.
