Boron tribromide → 3-Fluoro-5-methoxyphenol

Temperature

-15 °C

Under nitrogen atmosphere, 1-fluoro-3,5-dimethoxybenzene (25 g, 160 mmol) was diluted in CH2Cl2 (200 mL, 0.8M) and then cooled to −15° C. Next, BBr3 (176 mL, 176 mmol, 1M in CH2Cl2) was slowly added to the reaction mixture. The reaction mixture was stirred at −15° C. for one and a half hours and at room temperature for 10 minutes. The reaction mixture was then cooled to 0° C. and slowly quenched with water (150 mL). The aqueous layer was then extracted with methylene chloride (3×100 mL). The organic extracts were dried over sodium sulfate and concentrated. Silica gel chromatography (1%-30% EtOAc/Hexanes) gave the mono demethylated product (50-1) (15 g, 67%).

1. temperatureThe reaction mixture was then cooled to 0° C.
2. customslowly quenched with water (150 mL)
3. extractionThe aqueous layer was then extracted with methylene chloride (3×100 mL)
4. dry with materialThe organic extracts were dried over sodium sulfate
5. concentrationconcentrated

ORD record

ord-a0f9da0092ec42c08a64fc400a6ee268

Source dataset

uspto-grants-2010_10

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07807684B2