反应详情

In a 1 L single necked flask were charged 6-chloro-1H-pyrazolo[3,4-b]pyridine-4-carboxylic acid ethyl ester (10 g, 44.3 mmol) and dioxane (400 ml). To this resulting suspension were added a saturated solution of sodium hydrogen carbonate (0.5M, 260 ml) and iodine (11.2 g, 44.3 mmol). The reaction mixture was stirred at room temperature for 24 hours, iodine was then added (25 g, 97.5 mmol) and stirring was pursued for 48 hours. Next an aqueous sodium thiosulfate solution (0.9M) was added until complete decolouration and was poured into a solution of ice and HCl at pH=2. The mixture was filtered to afford the title compound as a yellow solid (14.7 g, 95%).

1. stirringstirring
2. waitwas pursued for 48 hours
3. filtrationThe mixture was filtered