Water → ethyl 1-({5-[3-(trifluoromethyl)phenyl]-1,3-oxazol-2-yl}methyl)-1H-pyrazole-4-carboxylate

The compound (0.73 g) obtained in Example 124a was dissolved in phosphorus oxychloride (10 mL), and the mixture was stirred at 110-130° C. overnight with heating. The reaction mixture was cooled to room temperature, slowly poured into water, and the mixture was extracted with ethyl acetate. The ethyl acetate layer was dried over sodium sulfate, and concentrated under reduced pressure. The residue was purified by column chromatography (carrier: silica gel, eluent: petroleum ether-ethyl acetate) to give the title compound (0.50 g) as a colorless solid.