反应详情

温度

100 °C

A mixture of 4-oxo-4-(2-phenylpyrazolo[1,5-a]pyridin-3-yl)crotonic acid (3.61 g), zinc powder (5.0 g) and acetic acid (50 ml) was heated at 100° C. for 1.5 hours. The zinc powder was filtered off and washed with acetic acid. The filtrate and washings were combined and evaporated in vacuo. To the residue a saturated aqueous solution of sodium hydrogen carbonate (50 ml) was added and extracted with ethyl acetate (50 ml×2). The combined extracts were washed with a saturated aqueous solution of sodium chloride (50 ml), dried over magnesium sulfate and evaporated in vacuo. The residue was recrystallized from ethanol to give crystals of 4-oxo-4-(2-phenylpyrazolo[1,5-a]pyridine-3-yl)butyric acid (1.65 g).

1. filtrationThe zinc powder was filtered off
2. washwashed with acetic acid
3. customevaporated in vacuo
4. additionTo the residue a saturated aqueous solution of sodium hydrogen carbonate (50 ml) was added
5. extractionextracted with ethyl acetate (50 ml×2)
6. washThe combined extracts were washed with a saturated aqueous solution of sodium chloride (50 ml)
7. dry with materialdried over magnesium sulfate
8. customevaporated in vacuo
9. customThe residue was recrystallized from ethanol