反应详情

Carbon tetrachloride (2 ml) was added to ethyl 2-(3-bromo-5-methyl-2H-indazol-2-yl)benzoate (0.450 g, 1.25 mmol) as obtained in Reference Example 4, and the mixture was stirred. Thereto were added N-bromosuccinimide (0.223 g, 1.25 mmol) and azobisisobutyronitrile (21 mg, 0.125 mmol), and the mixture was refluxed under heating for 3.5 hours. After cooling, it was filtered, and the cake was washed with dichloromethane (2 ml) and the filtrate was concentrated. The residue was then dissolved in DMF (2 ml), and added to a solution obtained by adding sodium hydride (40 mg, 1.00 mmol) to 2-ethyl-5,7-dimethyl-1H-imidazo[4,5-b]pyridine (0.176 mg, 1.00 mmol) in DMF (4 ml) and stirring the solution for 30 minutes. The mixture was stirred at room temperature for 30 minutes, concentrated, and partitioned by ethyl acetate (10 ml) and water (10 ml). The organic layer was dried over magnesium sulfate, and then filtered. The filtrate was concentrated and subjected to flash chromatography on silica gel using a mixed solvent of hexane/ethyl acetate (2:3), whereby 0.176 g of 3-[3-bromo-2-(2-ethoxycarbonylphenyl)-2H-indazol-5-yl]methyl-5,7-dimethyl-2-ethyl-3H-imidazo[4,5-b]pyridine was obtained.

1. customas obtained in Reference Example 4
2. temperaturethe mixture was refluxed
3. temperatureunder heating for 3.5 hours
4. temperatureAfter cooling
5. filtrationit was filtered
6. washthe cake was washed with dichloromethane (2 ml)
7. concentrationthe filtrate was concentrated
8. dissolutionThe residue was then dissolved in DMF (2 ml)
9. additionadded to a solution
10. customobtained
11. stirringstirring the solution for 30 minutes
12. stirringThe mixture was stirred at room temperature for 30 minutes
13. concentrationconcentrated
14. custompartitioned by ethyl acetate (10 ml) and water (10 ml)
15. dry with materialThe organic layer was dried over magnesium sulfate
16. filtrationfiltered
17. concentrationThe filtrate was concentrated