反应详情

温度

60 °C

A suspension of 6-nitro-2,2,3-trimethyl-4-(2-oxo-1,2-dihydropyridin-1-yl)-2H-1-benzopyran (1.62 g, 0.0052 mol) in carbon tetrachloride (10 ml) containing benzoyl peroxide (20 mg) was heated to 60° C. N-bromosuccinimide (0.92 g, 0.0052 mol) was added and the mixture heated at reflux for seventeen hours. The cooled solution was treated with dichloromethane and aqueous ferrous sulfate solution, the organic phase was separated and evaporated under reduced pressure. The residue was chromatographed on silica gel, eluting with dichloromethane/acetone (92.5/7.5). The product was washed with diethyl ether/pentane to give 1.49 g of 6-nitro-2,2-dimethyl-3-bromomethyl-4-(2-oxo-1,2-dihydropyridin-1-yl)-2H-1-benzopyran, m.p. 221° C.

1. temperaturethe mixture heated
2. temperatureat reflux for seventeen hours
3. customthe organic phase was separated
4. customevaporated under reduced pressure
5. customThe residue was chromatographed on silica gel
6. washeluting with dichloromethane/acetone (92.5/7.5)
7. washThe product was washed with diethyl ether/pentane