Sodium Carbonate → 7-bromo-3,4-dihydro-2H-1,5-benzodioxepine

To a mixture of 3,4-dihydro-2H-1,5-benzodioxepine (8.86 g) and sodium carbonate (9.4 g) in hexane (100 ml) was added dropwise at room temperature a solution of bromine. (3.0 ml) in hexane (30 ml) for 2.5 hours, and the mixture was stirred for 24 hours. To the mixture was added water, and the mixture was extracted with ethyl acetate. The organic layer was washed with saturated brine, dried with magnesium sulfate and concentrated under reduced pressure to give orange oil. To the obtained oil (13.39 g) in acetic acid (50 ml) was added sodium acetate (4.1 g), and then was added dropwise a solution of bromine (1.3 ml) in acetic acid (25 ml) for 1 hour. The mixture was stirred for 24 hours and concentrated under reduced pressure. To the residue was added water, and the mixture was extracted with ethyl acetate. The organic layer was washed with saturated brine, dried with magnesium sulfate and concentrated under reduced pressure. The residue was purified with silica gel column chromatography (ethyl acetate/hexane=1:4) to give orange oil of 7-bromo-3,4-dihydro-2H-1,5-benzodioxepine (13.17 g).

1. extractionthe mixture was extracted with ethyl acetate
2. washThe organic layer was washed with saturated brine
3. dry with materialdried with magnesium sulfate
4. concentrationconcentrated under reduced pressure
5. customto give orange oil
6. stirringThe mixture was stirred for 24 hours
7. concentrationconcentrated under reduced pressure
8. additionTo the residue was added water
9. extractionthe mixture was extracted with ethyl acetate
10. washThe organic layer was washed with saturated brine
11. dry with materialdried with magnesium sulfate
12. concentrationconcentrated under reduced pressure
13. customThe residue was purified with silica gel column chromatography (ethyl acetate/hexane=1:4)

ORD record

ord-83ddf207e284428887b00f7c949c00bd

Source dataset

uspto-grants-2001_05

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US06235771B1