Trifluoromethanesulfonic acid → 2,3-Difluoro-5-iodobenzoic acid

Participants

Reaction Conditions

Reaction Steps

A 500 mL, 3 neck round bottom flask, equipped with an overhead stirrer is charged with trifluoromethanesulfonic acid (100 g), cooled to 0-5° C. in an ice bath, and treated with 2,3-difluorobenzoic acid (18.96 g). To this mixture is added N-iodosuccinimide (32.4 g) portion-wise over a 10 min period. After an additional 3 min, the cooling bath is removed and the reaction mixture is allowed to warm to room temperature. After a total of 5 h, the reaction mixture is poured into 600 mL of vigorously stirred crushed ice/water containing 100 mL of 10% sodium sulfite solution. The beige colored precipitate is collected, washed with ice water and dried at 50° C. in a vacuum oven overnight to produce 28.2 g (83%) of the title compound. Physical characteristics: 1H NMR (CDCl3) δ10.35, 8.12, 7.76; MS (ESI−) m/z 283 (M−H)−.

Provenance & Evidence