Bromine → 5-Bromo-2,2-difluoro-1,3-benzodioxole

Iron powder (2.8 g, 50 mmol) was added to a solution of 2,2-difluoro-1,3-benzodioxole (15.8 g, 100 mmol) in carbon tetrachloride (200 mL) at 0° C. under a nitrogen atmosphere. Bromine (5.2 mL, 100 mmol) was then added to the mixture dropwise over 15 min. The reaction was heated to reflux for 1 h and then stirred at room temperature overnight. The mixture was filtered through Celite and the filtrate was washed with 0.1N sodium thiosulfate solution. The organic layer was then dried (MgSO4), filtered, and concentrated under reduced pressure to afford the title compound of Step A as an oil (15.2 g, 64%). 1H NMR (CDCl3): δ6.96 (m, 1H), 7.22 (m,2H).

1. temperatureThe reaction was heated
2. temperatureto reflux for 1 h
3. filtrationThe mixture was filtered through Celite
4. washthe filtrate was washed with 0.1N sodium thiosulfate solution
5. dry with materialThe organic layer was then dried (MgSO4)
6. filtrationfiltered
7. concentrationconcentrated under reduced pressure

ORD record

ord-938589f386a14a4bbc484da563c53622

Source dataset

uspto-grants-1997_05

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US05633218