2-AMINO-5-BROMO-3-FLUOROBENZOIC ACID

2-Amino-3-fluoro-benzoic acid (2.00 g, 12.9 mmol) was suspended in dichloromethane (34.0 mL) and N-bromosuccinimide (2.39 g, 12.9 mmol) was added in small portions at 0 °C. The reaction mixture was stirred at room temperature for 1 hour. The reaction mixture was filtered and the solid was washed with dichloromethane (30 mL) and dried in air for 15 min to give the desired product as a white solid (2.46 g, 10.5 mmol, 82percent Yield). LCMS: 0.82 min; ES+ 234/236 ( M+H+); [00535] Step 1: To a solution of 2-amino-3-fluorobenzoic acid (1.0 g, 6.45 mmol) in DMF (10 mL) at - 10 °C, NBS (1.15 g, 6.45 mmol) in DMF (4 mL) was added dropwise over 10 min. After the addition was complete, the reaction mixture was stirred at -10 °C for 1 h. The reaction was quenched with aqueous sodium bisulfate (50 mL) and large amount of solid precipitated out. The resulting solid was collected by filtration and dried in vacuum to afford 2-amino-5-bromo-3-fluorobenzoic acid (1.2 g, yield: 80percent) as a yellow solid.Step a. NBS (114.8 g, 645 mmol) was added in a portion wise manner over 1 h to a stirred orange/brown suspension of 2-amino-3-fluorobenzoic acid (100 g, 645 mmol) in DCM (1000 ml) at rt, and the resulting mixture was stirred at rt for 2 h. The mixture was then filtered and the resulting solid was washed sequentially with DCM (2 x 250 ml) and water (3 x 400 ml) before being dried under vacuum at 55°C for 7 h to give the desired product as a beige solid (121.4 g, 80percent). LCMS (Method S): rt 2.93 min, m/z 232/234 [M-H]-; NMR (400 MHz, DMSO-d6) δ ppm 7.64 (m, 1H), 7.52 (dd, J= 10.9, 2.3 Hz, 1H)Synthesis of 2-amino-5-bromo-3-fluorobenzoic acid. A solution of 2-amino-3-fluorobenzoic acid (10.85 g, 70 mmol) in dichloromethane (175 mL) was added N-bromosuccinimide (12.46 g, 70 mmol), and the mixture was stuffed at RT for 2 h. LCMS showed the reaction was completed. The precipitate was filtered and washed with dichloromethane (100 mL*3) to give the title compound (12.7 g, 78percent) as a grey solid, which was directly used in the next step without further purification. MS (ES+) C7H5BrFNO2 requires:233, 235, found: 232, 234 [M - H].A solution of 2-amino-3-fluorobenzoic acid (10.85 g, 70 mmol) in dichloromethane (175 mL) was added N-bromosuccinimide (12.46 g, 70 mmol), and the mixture was stirred at room temperature for 2 hours. The precipitate was filtered and washed with dichloromethane (100 mL*3) to give the title compound (12.7 g, 78percent) as a grey solid, which was directly used in the next step without further purification. MS (ES+) C