反应详情

To a solution of methyl 1H-indazole-5-carboxylate (2.5 g, 14 mmol) in DMF (45 mL) was added K2CO3 (4.90 g, 35.5 mmol) followed by iodomethane (1.77 mL, 28.4 mmol). The mixture was stirred at room temperature for 2 hours and then heated at 50° C. overnight. The mixture was concentrated, dissolved in EtOAc and washed with saturated aqueous NaCl. The organic extract was dried over Na2SO4, filtered and concentrated. The crude material was purified by CombiFlash (80 g column, 25-45% EtOAc/heptane) to provide methyl 1-methyl-1H-indazole-5-carboxylate (1.07 g, 40%) and methyl 2-methyl-2H-indazole-5-carboxylate (227 mg, 8.4%).

1. temperatureheated at 50° C. overnight
2. concentrationThe mixture was concentrated
3. dissolutiondissolved in EtOAc
4. washwashed with saturated aqueous NaCl
5. extractionThe organic extract
6. dry with materialwas dried over Na2SO4
7. filtrationfiltered
8. concentrationconcentrated
9. customThe crude material was purified by CombiFlash (80 g column, 25-45% EtOAc/heptane)