Oxygen → 1-Bromo-4-(bromodifluoromethyl)benzene

Under exclusion of oxygen, a solution of 14.0 g (67.63 mmol) of 1-bromo-4-(difluoromethyl)benzene (CAS 51776-71-7) and 25.3 g (142 mmol) of N-bromosuccinimide (NBS) in 190 ml of carbon tetrachloride is irradiated using a daylight lamp. During the radiation, the solvent reaches its boiling point. The mixture is irradiated under reflux for 24 hours. The mixture is then allowed to cool to room temperature, and precipitated succinimide is filtered off. Another 25 g of NBS are added to the filtrate, and the mixture is once more, under exclusion of oxygen, irradiated under reflux for 24 hours. After cooling, the mixture is again filtered and the filtrate is evaporated to dryness. This gives 18 g of a dark orange oil which is purified by vacuum distillation at 13 torr. This gives 12.7 g (44.4 mmol, 66% yield) of a colorless oil.

1. customThe mixture is irradiated
2. temperatureunder reflux for 24 hours
3. customprecipitated succinimide
4. filtrationis filtered off
5. additionAnother 25 g of NBS are added to the filtrate
6. customirradiated
7. temperatureunder reflux for 24 hours
8. temperatureAfter cooling
9. filtrationthe mixture is again filtered
10. customthe filtrate is evaporated to dryness
11. distillationThis gives 18 g of a dark orange oil which is purified by vacuum distillation at 13 torr

ORD record

ord-4da5e64d95ea4df2bf20ad3179c297a5

Source dataset

uspto-grants-2005_09

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US06939990B2