Boron tribromide → 3-Fluoro-5-methoxyphenol

Temperature

0 °C

Boron tribromide (1M in dichloromethane, 9 mL, 89.985 mmol) was added drop wise to an ice-cooled solution of 3,5-dimethoxy fluorobenzene (3 ml, 22.496 mmol) in dichloromethane (20 mL) and the mixture was stirred at 0° C. to room temperature for 4 hours. The solution was cooled to 0° C., further boron tribromide (4 ml, 44.992 mmol) was added and stirring continued, warming to room temperature for an additional 18 hours. The reaction was quenched with 0.88 ammonia solution and stirred at room temperature for 90 minutes. The organic layer was separated and extracted with 2N sodium hydroxide (30 ml), which was then acidified to pH1 by drop wise addition of concentrated hydrochloric acid. The aqueous layer was then re-extracted with dichloromethane (3×15 mL), the combined organic solution was dried over sodium sulfate and concentrated in vacuo to afford the title compound as a white solid in 54% yield, 1.72 g.

1. stirringstirring
2. temperaturewarming to room temperature for an additional 18 hours
3. customThe reaction was quenched with 0.88 ammonia solution
4. stirringstirred at room temperature for 90 minutes
5. customThe organic layer was separated
6. extractionextracted with 2N sodium hydroxide (30 ml), which
7. additionwas then acidified to pH1 by drop wise addition of concentrated hydrochloric acid
8. extractionThe aqueous layer was then re-extracted with dichloromethane (3×15 mL)
9. dry with materialthe combined organic solution was dried over sodium sulfate
10. concentrationconcentrated in vacuo

ORD record

ord-9717dda9e6a94e8da824433951a22ecc

Source dataset

uspto-grants-2013_07

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08486992B2