反应详情

温度

90 °C

To a stirred solution of methyl 6-bromo-1H-indazole-4-carboxylate (10 g, 39.3 mmol) in acetonitrile (100 mL), was added cesium carbonate (19.2 g, 59.05 mmol) followed by bromocyclopentane (11.93 g, 78.3 mmol). The reaction mass was stirred at 90° C. for 3-4 h. On completion of reaction, acetonitrile was removed under reduced pressure and water added. Extraction was carried out using ethyl acetate and the combined organic layers were washed with water, brine and dried over anhydrous Na2SO4. The solvent was removed under reduced pressure and the residue purified by silica gel column chromatography to obtain methyl 6-bromo-1-cyclopentyl-1H-indazole-4-carboxylate (3.7 g, 29.2%). The regiochemistry of the cyclopentyl group was confirmed by a NOE experiment.

1. customwas removed under reduced pressure and water
2. additionadded
3. extractionExtraction
4. washthe combined organic layers were washed with water, brine
5. dry with materialdried over anhydrous Na2SO4
6. customThe solvent was removed under reduced pressure
7. customthe residue purified by silica gel column chromatography