反应详情

To a solution of 7-bromo-2-methoxypyrazolo[1,5-a]pyridine (1 g) dissolved in acetic acid (10 mL) was added an aqueous solution (5 mL) of sodium nitrite (334 mg), and the reaction mixture was stirred for 20 minutes at room temperature. After adding ethanol (60 mL) and water (30 mL) to the reaction mixture, zinc powder (1 g) was added and the reaction mixture was heated and stirred for 30 minutes at 60° C. The reaction mixture was filtered through celite to remove insoluble residue, water was added and extraction was performed with ethyl acetate. The organic extract was washed with brine, dried over anhydrous magnesium sulfate and filtered, the solvent was evaporated under reduced pressure, the residue was purified by silica gel column chromatography and the title compound (750 mg) was obtained as brown crystals from the n-hexane:ethyl acetate (3:1) fraction.

1. additionwas added
2. temperaturethe reaction mixture was heated
3. stirringstirred for 30 minutes at 60° C
4. filtrationThe reaction mixture was filtered through celite
5. customto remove insoluble residue, water
6. additionwas added
7. extractionextraction
8. extractionThe organic extract
9. washwas washed with brine
10. dry with materialdried over anhydrous magnesium sulfate
11. filtrationfiltered
12. customthe solvent was evaporated under reduced pressure
13. customthe residue was purified by silica gel column chromatography