Dimethylformamide → N-phenyl-6-cyano-3-hydroxy-2,2-dimethyl-2H-1-benzopyran-4-carboxamide

Participants

Reaction Steps

To a mixture of 0.5 g of 6-cyano-3,4-dihydro-2,2-dimethyl-2H-1-benzopyran-3-one, 0.39 g of potassium t-butoxide, and 5 ml of dried N,N-dimethylformamide was added dropwise a mixture of 0.42 g of phenyl isocyanate and 1.5 ml of dried N,N-dimethylformamide while stirring under cooling with ice. After stirring for 4 hours under ice-cooling, ice-water was added thereto, and the mixture was made acidic with acetic acid and extracted with diethyl ether. The ether layer was washed with water and dried over sodium sulfate. Diethyl ether was removed by distillation, and the residue was purified by silica gel column chromatography (developing solution: CH2Cl2) to obtain 0.17 g of N-phenyl-6-cyano-3-hydroxy-2,2-dimethyl-2H-1-benzopyran-4-carboxamide represented by formula shown below.

Provenance & Evidence