3-Bromo-2-fluorobenzoic acid

1072-85-1

124-38-9

161957-56-8

1. n-Butyl lithium (n-BuLi, 240 mL of a 2.5 M solution, 600 mmol) was added dropwise to a tetrahydrofuran (THF, 500 mL) solution of diisopropylamine (84.3 mL, 600 mmol) at -30°C. 2. The resulting solution was stirred at -30°C for 30 minutes. 3. The mixture was added dropwise to a solution of 1-bromo-2-fluorobenzene (100 g, 571.43 mmol) in THF (500 mL) at -78° C. The solution was stirred for 30 minutes at -78° C. The mixture was then added to a solution of 1-bromo-2-fluorobenzene (100 g, 571.43 mmol). 4. After the addition, the resulting solution was stirred at -78°C for 2 hours. 5. The reaction mixture was poured over crushed solid carbon dioxide. 6. After removal of the solvent in vacuo, the resulting residue was diluted with water and washed with ether (2 x 500 mL). 7. The aqueous phase was acidified to pH 2 with 1N hydrochloric acid (HCl). 8. The precipitate was collected by filtration and dried to give 3-bromo-2-fluorobenzoic acid (90 g, 64% yield) as a white solid. 9. Mass spectrometry (MS) analysis showed m/z 221.0 (M + H+).