2905-54-6

50-45-3

2905-54-6

a) 2,3-Dichlorobenzoic acid (100 g, 0.526 mol) was dissolved in methanol (1 L) and concentrated sulfuric acid (20 mL) was added slowly. The reaction mixture was stirred under reflux conditions for 12 hours. After completion of the reaction, it was cooled to room temperature and concentrated under reduced pressure to remove most of the solvent. The residue was diluted with ethyl acetate (1 L) and water (100 mL) and the organic layer was separated. The organic phase was washed sequentially with saturated sodium bicarbonate solution and brine and dried over anhydrous sodium sulfate. After filtration, the filtrate was concentrated under reduced pressure to afford methyl 2,3-dichlorobenzoate (99 g, 92% yield) as a white solid.1H NMR (300 MHz, CDCl3) δ ppm: 3.95 (s, 3H), 7.27 (t, J = 7.8 Hz, 1H), 7.60 (dd, J = 1.8, 7.8 Hz, 1H), 7.66 (dd, J = 1.8, 7.8 Hz, 1H).