To a solution of 2,3-diamino-5-bromopyridine (5 g, 27 mmol) in tetrahydrofuran (THF, 87 mL) was added N,N'-carbonyl diimidazole (CDI, 3.02 g, 18.6 mmol). The reaction mixture was stirred at 80 °C for 16 hours. Upon completion of the reaction, water was added to quench the reaction and the mixture was filtered. The solid product was collected, washed sequentially with water and ether (Et2O), and dried under vacuum to afford 6-bromo-1H-imidazo[4,5-B]pyridin-2(3H)-one (5.3 g, 25 mmol, 93% yield), and the product could be used in subsequent reactions without further purification. Mass spectrometry (ESI) analysis: calculated value (C6H4BrN3O) 212.95; measured value, 214 [M + H]+.
![6-BROMO-1H-IMIDAZO[4,5-B]PYRIDIN-2(3H)-ONE](/CAS/GIF/148038-83-9.gif)