反应详情

温度

135 °C

A mixture of 2-phenylpyrazolo[1,5-a]pyridine (0.50 g, 2,4-piperidinedione (0.292 g), concentrated sulfuric acid (1 drop) and acetic acid (0.5 ml) was heated at 135° C. for 13.5 hours. A saturated aqueous solution of sodium hydrogen carbonate (20 ml) was added to the reaction mixture and the mixture was extracted with chloroform (20 ml×2). The combined extract was washed with a saturated aqueous solution of sodium chloride (20 ml) and dried over magnesium sulfate. The solvent was evaporated in vacuo. The residue was purified by column chromatography on silica gel using a mixture of chloroform and ethyl acetate (9:1) and recrystallized from ethyl acetate to give crystals of 3-(2-oxo-1,2,5,6-tetrahydropyridin-4-yl)-2-phenylpyrazolo[1,5-a]pyridine.

1. extractionthe mixture was extracted with chloroform (20 ml×2)
2. extractionThe combined extract
3. washwas washed with a saturated aqueous solution of sodium chloride (20 ml)
4. dry with materialdried over magnesium sulfate
5. customThe solvent was evaporated in vacuo
6. customThe residue was purified by column chromatography on silica gel using
7. additiona mixture of chloroform and ethyl acetate (9:1)
8. customrecrystallized from ethyl acetate