反应详情

1.0 g of 2,2-dimethyl-4-(2-pyrimidinyl)-2H-1-benzopyran-6-carbonitrile was dissolved in 100 ml of ethanol, added to 10% palladium-on-charcoal and shaken under an atmosphere of hydrogen at room temperature. After 2 hours the catalyst was filtered off and the filtrate was evaporated. The residue was chromatographed on silica gel using ethyl acetate/petroleum ether (1:1) for the elution. The product was recrystallized from cyclohexane to give 0.5 g of 3,4-dihydro-2,2-dimethyl-4-(2-pyrimidinyl)-2H-1-benzopyran-6-carbonitrile of melting point 109°-111° C.

1. filtrationAfter 2 hours the catalyst was filtered off
2. customthe filtrate was evaporated
3. customThe residue was chromatographed on silica gel
4. washfor the elution
5. customThe product was recrystallized from cyclohexane