25391-57-5

4214-75-9

25391-57-5

To a 250 mL three-necked flask were added 2-amino-3-nitropyridine (10.0 g, 72.0 mmol), acetic acid (44 mL) and water (10 mL). The mixture was heated to 90°C and then periodic acid (3.28 g, 14.4 mmol) and concentrated sulfuric acid (1.3 mL) at a mass percent concentration of 98% were added sequentially. After stirring for 10 min, iodine (9.1 g, 36.0 mmol) was added and stirring was continued for 60 min at this temperature. Upon completion of the reaction, the reaction solution was cooled to room temperature and subsequently poured into saturated aqueous sodium thiosulfate solution (100 mL). The solid product was separated by filtration and washed sequentially with saturated brine (50 mL x 2) and petroleum ether (50 mL x 2). The crude product was recrystallized using a mixed solvent of petroleum ether and ethyl acetate (5:1, v/v) to afford a high purity yellow solid 2-amino-5-iodo-3-nitropyridine (17.57 g, 69.1 mmol, 96% yield).