Acetic Acid → 2-Bromo-4-(trifluoromethyl)benzoic acid

Participants

Reaction Conditions

Reaction Steps

205 g (1 mol) of 4-(trifluoromethyl)anthranilic acid, 600 ml of glacial acetic acid and 400 ml of 47% hydrobromic acid are introduced successively into a three-liter round-bottomed flask. After dissolution, the reaction mixture is cooled to -10° C., diluted with 400 ml of water and then treated dropwise with a solution of 69 g (1 mol) of sodium nitrite in 200 ml of water while maintaining the temperature below 0° C. When the addition is finished, the reaction mixture is stirred at 0° C. for 2 hours. This solution is run in dropwise into a six-liter reactor containing 143.5 g (1 mol) of cuprous bromide in 500 ml of 47% hydrobromic acid maintained at 60° C. When the addition is finished, the reaction mixture is stirred at 60° C. for one hour, cooled to room temperature and then poured into two liters of ice-cold water. The precipitate which forms is filtered on sintered glass, washed with water and then dried under a stream of air. There is thus obtained 216 g (yield: 80%) of 2-bromo-4-(trifluoromethyl)benzoic acid in the form of a solid melting at 118.5° C.

Provenance & Evidence