Water → 2-Bromo-5-hydroxybenzoic acid

Temperatur

-60 °C

A mixture of 2-bromo-5-methoxybenzoic acid (10 g, 0.043 mol) in methylene chloride is cooled to -60° C., treated with boron tribromide (3.59 g, 0.143 mol), stirred at -60° C. for 1 hour, stirred at room temperature for 1 hour, cooled to -70° C., treated with additional boron tribromide (3.59 g, 0.143 mol), stirred at -70° C. for 1 hour, stirred at room temperature for 1 hour and poured into water. The aqueous mixture is extracted with ethyl acetate. The organic extracts are combined, washed with brine, dried over anhydrous sodium sulfate and concentrated in vacuo to give the title product as a white solid which is identified by 1H and 13CNMR spectral analyses.

1. stirringstirred at room temperature for 1 hour
2. temperaturecooled to -70° C.
3. stirringstirred at -70° C. for 1 hour
4. stirringstirred at room temperature for 1 hour
5. extractionThe aqueous mixture is extracted with ethyl acetate
6. washwashed with brine
7. dry with materialdried over anhydrous sodium sulfate
8. concentrationconcentrated in vacuo

ORD-Eintrag

ord-2726bc7ace624f1ba7915be10bcba01f

Quelldatensatz

uspto-grants-1997_08

DOI

10.6084/m9.figshare.5104873.v1

Patentnummer

US05654256