反应详情

Carbon tetrachloride (26 ml) was added to ethyl 2-(5-methyl-2H-indazol-2-yl)benzoate (1.43 g, 5.10 mmol) as obtained in Reference Example 3 and the mixture was stirred. Thereto were added N-bromosuccinimide (0.908 g, 5.10 mmol) and azobisisobutyronitrile (78 mg, 0.48 mmol), and the mixture was refluxed under heating for 3 hours. After cooling, the mixture was filtered, and the cake was washed twice with carbon tetrachloride (5 ml). The filtrate was concentrated, and subjected to flash chromatography on silica gel using a mixed solvent of hexane/ethyl acetate (8:1-3:1), whereby 1.47 g of ethyl 2-(3-bromo-5-methyl-2H-indazol-2-yl)benzoate was obtained.

1. customas obtained in Reference Example 3
2. temperaturethe mixture was refluxed
3. temperatureunder heating for 3 hours
4. temperatureAfter cooling
5. filtrationthe mixture was filtered
6. washthe cake was washed twice with carbon tetrachloride (5 ml)
7. concentrationThe filtrate was concentrated