反应详情

To a mixture of 1.01 g of N-[4-chloro-2-hydroxy-5-(trifluoromethyl)phenyl]isonicotinamide, 10 ml of tetrahydrofuran and 0.92 g of triphenylphosphine, 1.53 g of 40% toluene solution of diethyl azodicarboxylate was added dropwise at room temperature, and the reaction mixture was stirred for two hours. The reaction mixture was concentrated under reduced pressure. The residue was subjected to silica gel column chromatography and the resultant crystals washed with methanol to give 0.66 g of 6-chloro-2-(pyridin-4-yl)-5-(trifluoromethyl)benzoxazole (hereinafter, referred to as “active compound 80”).

1. additionwas added dropwise at room temperature
2. concentrationThe reaction mixture was concentrated under reduced pressure
3. washthe resultant crystals washed with methanol