In a solution of 0.47 g of [bis(trifluoroacetoxy)iodo]benzene in 12 ml of acetonitrile-water (1:1), a solution of 0.47 g of N-carbamoylmethyl-4-[5-(3,5-dichlorophenyl)-5-trifluoromethyl-4,5-dihydroisoxazol-3-yl]-2-methyl benzoic acid amide synthesized in Synthetic Example 31 was added with stirring at room temperature, and stirred at room temperature for 5 hours. After the completion of the reaction, 75 ml of water was added in the reaction mixture, 8 ml of concentrated hydrochloric acid was added, then washed with 100 ml of diethyl ether, and the organic phase was subjected to back extraction with 2N hydrochloric acid aqueous solution (20 ml×2). The aqueous phase was combined with the organic phase, water was distilled off, and the residual solid was washed with ethyl acetate to obtain 0.21 g of the aimed product as white crystal. Melting point 155.0 to 157.0° C.
