反应详情

With efficient stirring, 283 g. (1.77 moles) of bromine are added dropwise at 0°-5° C. to a mixture of 237 g (1.77 moles) of 2,3-dihydro-2-methylbenzo[b]furan, 148.7 g (1.77 moles) of sodium bicarbonate, 500 ml of methylene chloride and 500 ml of water. When the addition of bromine is complete, the mixture is stirred for another 1/2 hour at 20°-25° C. The organic phase is separated, dried over sodium sulfate, concentrated and fractionated in vacuo. Yield: 242 g (66% of theory) of 5-bromo-2,3-dihydro-2-methylbenzo[b]furan and 77 g (15% theory) of 5,7-dibromo-2,3-dihydro-2-methylbenzo[b]furan.

1. customThe organic phase is separated
2. dry with materialdried over sodium sulfate
3. concentrationconcentrated