Tetrahydrofuran → 5-Chloro-2-(3-chloropyridin-4-yl)-6-(trifluoromethyl)benzoxazole

Participants

Reaction Steps

To a mixture of 0.67 g of 3-chloro-N-[5-chloro-2-hydroxy-4-(trifluoromethyl)phenyl]isonicotinamide, 7 ml of tetrahydrofuran and 0.55 g of triphenylphosphine, 0.91 g of 40% toluene solution of diethyl azodicarboxylate was added dropwise at room temperature. The reaction mixture was stirred for 1.5 hours. To the mixture, 0.14 g of triphenylphosphine and 0.23 g of 40% toluene solution of diethyl azodicarboxylate were added and stirred for further one hour. The reaction mixture was concentrated under reduced pressure. The residue was subjected to silica gel column chromatography, and the resultant crystals were washed with isopropanol and hexane to give 0.37 g of 5-chloro-2-(3-chloropyridin-4-yl)-6-(trifluoromethyl)benzoxazole (hereinafter, referred to as “active compound 79”).

Provenance & Evidence