Hydrogen Bromide → 3-Bromo-4-(trifluoromethyl)benzoic acid

Temperatur

75 °C

3-Amino-4-trifluoromethylbenzoic acid (8.20 g, 40.0 mmol), prepared according to Astrid Giencke and Helmut Lackner, Liebigs Ann. Chem., 569-579:6 (1990), in 48% HBr (20 mL) and H2O (67 mL) at 0° C. was treated with NaNO2 (2.99 g) in small portions over 15 minutes. After stirring for 30 minutes, the mixture was treated with urea (0.250 g) and then the mixture was added dropwise to a solution of CuBr (10.0 g) in 48% HBr (40 mL) and H2O (100 mL). The reaction mixture was heated at 75° C., stirred for 2 hours, cooled to room temperature, and stirred overnight. The mixture was treated with 20% NaOH until the pH>10. The resulting blue copper salts were removed by filtration through Celite. The mixture was acidified to pH 1 with HCl, extracted with CH2Cl2 (3×200 mL), dried over Na2SO4, filtered, and the filtrate was concentrated under reduced pressure to provide the title compound.

1. stirringstirred for 2 hours
2. temperaturecooled to room temperature
3. stirringstirred overnight
4. customThe resulting blue copper salts were removed by filtration through Celite
5. extractionextracted with CH2Cl2 (3×200 mL)
6. dry with materialdried over Na2SO4
7. filtrationfiltered
8. concentrationthe filtrate was concentrated under reduced pressure

ORD-Eintrag

ord-3f7c81b28cc94f25a91d4bda91786269

Quelldatensatz

uspto-grants-2012_08

DOI

10.6084/m9.figshare.5104873.v1

Patentnummer

US08247413B2