反应详情

2.96 g of 2,2-dimethyl-4-(2-pyridyl)-2H-1-benzopyran-6-carbonitrile were dissolved in 100 ml of ethanol and added at room temperature to 100 mg of 10% palladium-on-charcoal. The mixture was shaken at room temperature under a hydrogen atmosphere for 2 hours. The catalyst was then removed by filtration and the filtrate was evaporated. The residue was chromatographed on silica gel using ethyl acetate/petroleum ether(1:2) for the elution. There were obtained 2.44 g of 3,4-dihydro-2,2-dimethyl-4-(2-pyridyl)-2H-1-benzopyran-6-carbonitrile of melting point 114°-115° C.

1. customThe catalyst was then removed by filtration
2. customthe filtrate was evaporated
3. customThe residue was chromatographed on silica gel
4. washfor the elution