Hydrogen Bromide → 1-Bromo-3-(bromomethyl)-5-fluorobenzene

While phosphorus tribromide (3.65 g) was stirred, 47% aqueous hydrogen bromide solution (18.3 ml) was added in such a manner that the reaction temperature did not exceed 40° C. 3-Bromo-5-fluorobenzyl alcohol (7.70 g) in ethanol (6 ml) was added dropwise thereto, and the mixture was refluxed for 5 hours in an oil bath. The reaction mixture was cooled, and poured into ice/water, followed by extraction with n-hexane (150 ml). The organic layer was washed with saturated brine, and dried over magnesium sulfate. The solvent was evaporated under reduced pressure, and the residue was purified by silica gel column chromatography (n-hexane:ethyl acetate=30:1), to thereby yield 6.64 g of the target compound (yield: 66.0%).

1. customdid not exceed 40° C
2. temperaturethe mixture was refluxed for 5 hours in an oil bath
3. temperatureThe reaction mixture was cooled
4. extractionfollowed by extraction with n-hexane (150 ml)
5. washThe organic layer was washed with saturated brine
6. dry with materialdried over magnesium sulfate
7. customThe solvent was evaporated under reduced pressure
8. customthe residue was purified by silica gel column chromatography (n-hexane:ethyl acetate=30:1)

ORD record

ord-d86f8e0068864e19b3a34761c0b2cad0

Source dataset

uspto-grants-2003_07

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US06586633B1