General procedure for the synthesis of 2,6-dibromo-3-hydroxypyridine from 3-hydroxypyridine: Ice-cold bromine (16.2 mL, 315 mmol) was added dropwise to a stirring 2.5 M sodium hydroxide solution (320 mL, 800 mmol). This mixed solution was then slowly added to a 2.5 M sodium hydroxide solution (110 mL, 275 mmol) containing 3-hydroxypyridine (10.0 g, 105 mmol). The reaction mixture was stirred at 0 °C for 1 hour, followed by continued stirring at room temperature for 4 hours. Upon completion of the reaction, a small amount of precipitate was removed by filtration. The filtrate was cooled and the pH was adjusted to 1 with concentrated hydrochloric acid, at which point a solid precipitated. The solid product was collected by filtration, washed with water, dried, and recrystallized from carbon tetrachloride to give 2,6-dibromo-3-hydroxypyridine (12.1 g, 46% yield) as a beige solid. The product was characterized by 1H NMR (400 MHz, DMSO-d6): δ= 11.14 (br s, 1H), 7.47 (d, J = 8.0 Hz, 1H), 7.26 (d, J = 8.0 Hz, 1H); mass spectra (ES-ve) m/z: 250, 252, 254 (M-H)-.
