Hydrogen Bromide → 2,3-Dibromo-5-methylbenzoic acid

Participants

Reaction Steps

To a solution of 3-bromo-5-methylanthranilic acid (2.3 g, 10 mmol) in acetic acid (12 mL) at 0° C. was added 18% hydrobromic acid (30 mL, 30 mmol) followed by drop wise addition of a solution of sodium nitrite (690 mg, 10 mmol) in water (5 mL). After 10 min, this solution was added to a mixture of copper (I) bromide (2.15 g, 15 mmol) in 48% hydrobromic acid (7 mL) at 0° C. The mixture was allowed to warm to ambient temperature (15 minutes) and then refluxed at 50° C. until evolution of N2 was completed. The mixture was then extracted with ethyl acetate, washed with water, brine, dried with anhydrous magnesium sulfate and concentrated under reduced pressure to provide 2.8 g of crude of the title compound. 1H NMR (300 MHz, DMSO-d6) δ 2.27 (s, 3H), 7.43 (s, 1H), 7.72 (s, 1H), 13.60 (br s, 1H); MS (DCI/NH3) m/e 310 (M+NH4)+.

Provenance & Evidence