反应详情

406 mg of m-chloroperbenzoic acid were added to a solution of 524 mg of 2,2-dimethyl-4-(2-pyridyl)-2H-1-benzopyran-6-carbonitrile in 15 ml of dichloromethane at room temperature. After stirring at room temperature for 17 hours the solution was washed with sodium bicarbonate solution. The organic phase was dried over sodium sulphate and evaporated. The residue was chromatographed on silica gel using methanol/ethyl acetate (1:4) for the elution. There were obtained 240 mg of 2-(6-cyano-2,2-dimethyl-2H1-benzopyran-4-yl)pyridine N-oxide of melting point 187°-189° C. after recrystallization from ethyl acetate.

1. washwas washed with sodium bicarbonate solution
2. dry with materialThe organic phase was dried over sodium sulphate
3. customevaporated
4. customThe residue was chromatographed on silica gel
5. washfor the elution