Hydrogen Bromide → 2-Bromo-3-fluorobenzoic acid

Participants

Reaction Conditions

Reaction Steps

In a 1 L, three necked, round-bottomed flask fitted with a dropping funnel and a thermometer, were charged 20 g (0.13 mol) of 2-amino-3-fluoro-benzoic acid and 160 mL of acetonitrile. After cooling to 0° C., 160 mL of hydrobromic acid (47%) was added dropwise over 10 min. To the resulting solution, 10 g of NaNO2 (0.145 mol) in water (20 mL) was added dropwise over 1 hour. After addition, the reaction mixture was stirred at 0° C. for 5 min, and 21.8 g of Cu(I) Br (0.15 mol) was added portionwise over 30 min. Stirring was continued at 70° C. in an oil bath for 1 hour. After cooling to 0° C., 700 mL of H2O was added and the precipitate was filtered, washed with cold water and dried under vacuum to give an orange solid corresponding to 2-bromo-3-fluoro-benzoic acid (22 g, 78%).

Provenance & Evidence