2-Bromo-5-iodopyridine

20511-12-0

73290-22-9

General procedure for the synthesis of 2-bromo-5-iodopyridine from 2-amino-5-iodopyridine: Bromine (3 mL) was slowly added dropwise to a mixture of 2-amino-5-iodopyridine (5 g, 20 mmol) dissolved in 48% aqueous hydrobromic acid (10 mL), and the reaction system was cooled by an ice bath to maintain the reaction at low temperature. Subsequently, sodium nitrite (3.4 g, dissolved in 5 mL of water) solution was added dropwise, and the reaction temperature was controlled not to exceed 15 °C. After the dropwise addition, a solution of sodium hydroxide (16 g) in water (40 mL) was added. A brown solid precipitated from the reaction mixture and was extracted with dichloromethane (50 mL). The organic phases were combined, washed sequentially with water and saturated saline, dried over anhydrous magnesium sulfate, and concentrated under reduced pressure to afford the target product 2-bromo-5-iodopyridine (4.4 g, 78% yield).