Thionyl chloride (4.0 ml) was added to 2-methoxycarbonyl-3-[4-(2-(5-ethyl-2-phenyl-4-oxazolyl)ethoxy]phenyl]propionic acid (4.10 g, 10.0 mmol) obtained in Example 1 and the mixture was stirred with heating at 60° C. for 1 hr. Excess thionyl chloride was evaporated under reduced pressure and urea (900 mg, 15.0 mmol) was added to the residue obtained, which was followed by stirring with heating at 100° C. for 45 min. Chloroform (100 ml) and water (50 ml) were added for partition. The organic layer was washed with saturated brine (50 ml), dried over magnesium sulfate and concentrated under reduced pressure. The obtained residue was purified by silica gel column chromatography (developing solvent; n-hexane:ethyl acetate=1:1) to give the title compound (3.71 g, yield 82%) as a white solid.
