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ChemicalBook CAS DataBase List 3-Bromo-2-fluorobenzoic acid
161957-56-8

3-Bromo-2-fluorobenzoic acid synthesis

5synthesis methods
-

Yield:161957-56-8 64%

Reaction Conditions:

Stage #1: o-fluorobromobenzenewith n-butyllithium;N-ethyl-N,N-diisopropylamine in tetrahydrofuran at -78; for 2 h;
Stage #2: carbon dioxide in tetrahydrofuran;
Stage #3: with hydrogenchloride in water; pH=2;

Steps:

7

INTERMEDIATE PREPARATION 76-bromo-7-fluoro-1 /-/-indole-2,3-dione3-bromo-2-fluorobenzoic acidTo a solution of diisopropylamine (84.3 mL, 600 mmol) in THF (500 mL) at -30°C was added n-BuLi (240 mL of a 2.5M solution, 600 mmol) dropwise. The resulting solution was stirred at -30°C for 30 min. This mixture was added dropwise to a solution of 1-bromo-2- fluorobenzene (100 g, 571 .43 mmol) in THF (500 mL) at -78°C. After the addition was complete, the resulting solution was stirred at -78°C for 2 h and poured over crushed solid C02. After removal of the solvent in vacuo, the resulting residue was diluted with water and washed with diethyl ether (2 x 500 mL). The aqueous phase was acidified with 1 N HCI to pH 2. The precipitate was collected by filtration and dried to afford 3-bromo-2-fluorobenzoic acid (90 g, 64% yield) as a white solid. MS (m/z) 221.0 (M+H+).

References:

WO2011/119704,2011,A1 Location in patent:Page/Page column 39-40

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