反应详情

A solution of 215 ml of bromine in 450 ml of methylene chloride is added dropwise over 21/2 hours to an ice-cooled mixture of 562.3 g of 2,3-dihydro-2-methylbenzo[b]furan, 1600 ml of methylene chloride, 1600 ml of water and 352.5 g of sodium bicarbonate. After the mixture has been stirred for another 11/2 hours at the same temperature, the aqueous phase is separated and extracted with two 300 ml portions of methylene chloride. The combined organic phases are washed with 2×250 ml of water, dried over sodium sulfate and concentrated. After removal of all constituents having a boiling point below 99° C. under a pressure of 8 mbar, there are obtained 750.7 g of 5-bromo-2,3-dihydro-2-methylbenzo[b]furan as residue.

1. temperaturecooled
2. customthe aqueous phase is separated
3. extractionextracted with two 300 ml portions of methylene chloride
4. washThe combined organic phases are washed with 2×250 ml of water
5. dry with materialdried over sodium sulfate
6. concentrationconcentrated
7. customAfter removal of all constituents