281 mg (7.03 mmol, 10 eq) of sodium hydroxide are added to a solution of 400 mg (0.703 mmol, 1 eq) of methyl 3-[3′-(3-heptyl-1-methylureido)-2-(3-methylbutoxy)biphenyl-4-yl]propanoate in 10 ml of methanol. The reaction mixture is heated at 55° C. for 1 hour. The reaction medium is evaporated to dryness, taken up in water, acidified with 2N hydrochloric acid solution and extracted with ethyl acetate. The organic phases are combined, washed with water and dried over magnesium sulfate. The solvent is evaporated off and the oil obtained is chromatographed on silica gel (10 g FlashSmart column) eluted with 30/70 heptane/ethyl acetate. The product is crystallized from heptane and 284 mg of 3-[3′-(3-heptyl-1-methylureido)-2-(3-methylbutoxy)biphenyl-4-yl]propanoic acid are obtained in the form of white crystals (m.p.=60-62° C.). Yield=84%
