First, 0.13 g of 1-[3-(dimethylamino)propyl]-3-ethylcarbodiimide hydrochloride was added to a mixture of 0.30 g of [3-{2-chloro-4-fluoro-5-[3-methyl-2,6-dioxo-4-(trifluoromethyl)-1,2,3,6-tetrahydropyrimidin-1-yl]phenoxy}-2-pyridyloxy]acetic acid (compound a-2), 49 mg of acetone oxime, and 2 ml of N,N-dimethylformamide at room temperature, and the mixture was stirred for 2 hours. The mixture was poured into water, and the mixture was extracted with ethyl acetate. The organic layer was dried over anhydrous magnesium sulfate and then concentrated. The residue was subjected to silica gel column chromatography to give 0.16 g of acetone O-[3-{2-chloro-4-fluoro-5-[3-methyl-2,6-dioxo-4-(trifluoromethyl)-1,2,3,6-tetrahydropyrimidin-1-yl]phenoxy}-2-pyridyloxy]acetyloxime (compound a-98).
