Step 2: Synthesis of 3-amino-5-bromopyridine-2-carboxylic acid
To a 100 mL round bottom flask was added 3-amino-5-bromopyridine-2-carboxamide (1.05 g, 4.9 mmol) and aqueous sodium hydroxide solution (0.98 g dissolved in 10 mL of water, 24.5 mmol). The reaction mixture was heated to reflux temperature and stirred for 5 hours. Upon completion of the reaction, volatiles were removed by distillation under reduced pressure to give a residue. The residue was neutralized with 2N HCl at 0 °C to pH=7.0 and precipitate was precipitated. The precipitate was collected by filtration and dried to give 3-amino-5-bromopyridine-2-carboxylic acid as a light yellow solid (1 g, 95% yield).
1H NMR (300 MHz, DMSO-d6): δ 7.65 (d, J=2.1 Hz, 1H), 7.20 (d, J=2.1 Hz, 1H), 7.01-7.16 (br s, 2H).
LC-MS (ESI): calculated: 215.9; measured: 217.0 [M+H]+ (RT: 0.43 min).
