16 mg (0.4 mmol) of sodium hydroxide are added to a solution of 70 mg (0.42 mmol) of methyl (S)-2-benzyloxy-3-[3′-(3-heptyl-1-methylureido)biphenyl-4-yl]propanoate in 2 ml of 9/1 tetrahydrofuran/methanol. The reaction mixture is stirred overnight at ambient temperature. The reaction is halted by the addition of 2 ml of water and 0.5 ml of acetic acid, and then extraction is carried out with ethyl acetate. The organic phases are combined and dried over sodium sulfate. The solvents are evaporated and then the residue is chromatographed on silica gel (dichloromethane/methanol 90/10). 49 mg of 2(S)-benzyloxy-3-[3′-(3-heptyl-1-methylureido)biphenyl-4-yl]propanoic acid are obtained in the form of an oil. Yield=72%.
