反应详情

温度

0 °C

Sodium hydride (47 mg, 60% in mineral oil, 1.18 mmol) was added in portions to a solution of 5-bromo-1H-pyrazolo[3,4-b]pyridine-3-carboxylic acid methyl ester Compound 1b (0.3 g, 1.17 mmol) in dry THF (20 mL) at 0° C. The mixture was stirred at 0° C. for 15 minutes then methyl iodide (80 μl, 1.29 mmol) was added. The reaction was warmed to room temperature gradually and stirred overnight. the solvent was removed and the residue was purified by silica gel chromatography (10% to 50% of ethyl acetate in hexanes) to yield 5-bromo-1-methyl-1H-pyrazolo[3,4-b]pyridine-3-carboxylic acid methyl ester Compound 11a (0.31 g, 97% yield) as a white powder. 1H NMR (400 MHz, CDCl3) δ 9.89 (s, 2H), 4.51 (s, 3H), 3.37 (s, 3H); MS (ESI) m/z: 271 (M+H+).

1. temperatureThe reaction was warmed to room temperature gradually
2. stirringstirred overnight
3. customthe solvent was removed
4. customthe residue was purified by silica gel chromatography (10% to 50% of ethyl acetate in hexanes)