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

Temperature

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 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 record

ord-84ffc26937d646a1b7749c7de8a3b322

Source dataset

uspto-grants-2008_02

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07335678B2