0.93 mL (0.93 mmol) of aqueous 1 M lithium hydroxide solution is added to a solution of 0.29 g (0.62 mmol) of ethyl (Z)-2-ethoxy-3-{4-[6-(3-heptyl-1-methylureido)pyrid-2-yl]phenyl}acrylate in 8 mL of tetrahydrofuran. The reaction mixture is stirred at 68° C. for 18 hours. After cooling, the reaction is worked up by addition of 0.93 mL (0.93 mmol) of aqueous 1 M acetic acid solution and 10 mL of water and extraction with ethyl acetate. The organic phases are combined, washed with saturated sodium chloride solution and then dried over magnesium sulfate. After filtration, the solvents are evaporated off. The crude product obtained is purified by chromatography on a column of silica eluted with a 60/40 heptane/ethyl acetate mixture to give 0.10 g (37%) of (Z)-2-ethoxy-3-{4-[6-(3-heptyl-1-methylureido)pyrid-2-yl]phenyl}acrylic acid in the form of a white solid.
