Chloroform → 2-(2-Chloro-1-oxido-4-pyridinyl)-5-(trifluoromethyl)benzoxazole

Participants

Reaction Conditions

Reaction Steps

To a mixture of 0.40 g of 2-(2-chloropyridin-4-yl)-5-(trifluoromethyl)benzoxazole and 4 ml of chloroform, 0.53 g of 65% m-chloroperbenzoic acid was added while ice-cooling. The reaction mixture was stirred while ice-cooling for 30 minutes, then stirred at room temperature for three hours, and then stirred while heating at 50° C. for 1.5 hours. To the mixture, 0.53 g of 65% m-chloroperbenzoic acid and 2 ml of chloroform were added and stirred while heating at 60° C. for five hours. The reaction mixture was cooled to room temperature, then diluted with ethyl acetate, and washed with 5% aqueous solution of sodium hydroxide and a saturated sodium chloride solution, sequentially. The organic layer was dried over anhydrous sodium sulfate and then concentrated under reduced pressure to give 0.38 g of 2-chloro-4-[5-(trifluoromethyl)benzoxazole-2-yl]pyridine N-oxide (hereinafter, referred to as “active compound 22”).

Provenance & Evidence