3-[3-Chloro-4-(hydroxymethyl)phenyl]-5-(3,5-dichlorophenyl)-5-trifluoromethyl-4,5-dihydroisoxazole → 2-Chloro-4-[5-(3,5-dichlorophenyl)-5-trifluoromethyl-4,5-dihydro-isoxazol-3-yl]benzaldehyde

In a solution of 2.0 g of 3-[3-chloro-4-(hydroxymethyl)phenyl]-5-(3,5-dichlorophenyl)-5-trifluoromethyl-4,5-dihydroisoxazole in 60 mL of dichloromethane, 4.0 g of silica gel and 1.3 g of pyridinium chlorochromate were added, and stirred at room temperature for 20 hours. After the completion of the reaction, the reaction mixture was filtered through glass filter in which silica gel was packed to separate a solid with a solvent. The solvent was distilled off under reduced pressure. The residual solid was washed with diisopropyl ether to obtain 1.45 g of the aimed product as pale yellow crystal.