反应详情

To a stirring solution of the above benzofuran (5.00 g, 28.25 mmol) and benzoyl peroxide (0.68 g, 2.83 mmol) in carbon tetrachloride (200 mL) was added 1,3-dibromo-5,5-dimethylhydantoin (4.04 g, 14.12 mmol). The mixture was irradiated with a 200 watt lamp while stirring for 1 hour, cooled and partitioned between dichloromethane/water. The organic phase was washed with water (2×100 mL) and brine (2×100 mL), dried (MgSO4), decolorized (charcoal), and concentrated in vacuo to afford 7.12 g of crude product. Recrystallization from ethyl acetate/hexane afforded 4.38 g (61%) of 2-bromomethyl-5-nitro-benzofuran as an off-white solid: 1H NMR (CDCl3): δ 8.49 (d, 1H), 8.25 (dd, 1H), 7.58 (d, 1H), 6.91 (s, 1H), 4.59 (s, 2H).

1. customThe mixture was irradiated with a 200 watt lamp
2. temperaturecooled
3. custompartitioned between dichloromethane/water
4. washThe organic phase was washed with water (2×100 mL) and brine (2×100 mL)
5. dry with materialdried (MgSO4)
6. concentrationconcentrated in vacuo
7. customto afford 7.12 g of crude product
8. customRecrystallization from ethyl acetate/hexane