4-Oxo-4-(2-phenylpyrazolo[1,5-a]pyridin-3-yl)crotonic acid → 4-Oxo-4-(2-phenylpyrazolo[1,5-a]pyridin-3-yl)butyric acid
Reaction equation
[O:1]=[C:2]([C:8]1[C:9]([C:17]2[CH:22]=[CH:21][CH:20]=[CH:19][CH:18]=2)=[N:10][N:11]2[CH:16]=[CH:15][CH:14]=[CH:13][C:12]=12)/[CH:3]=[CH:4]/[C:5]([OH:7])=[O:6]>[Zn].C(O)(=O)C>[O:1]=[C:2]([C:8]1[C:9]([C:17]2[CH:22]=[CH:21][CH:20]=[CH:19][CH:18]=2)=[N:10][N:11]2[CH:16]=[CH:15][CH:14]=[CH:13][C:12]=12)[CH2:3][CH2:4][C:5]([OH:7])=[O:6]Participants
4
Reactant 1
Product 1
Reagents, catalysts & solvents 2
Conditions
- Temperature
- 100 °C
Procedure
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]pyridin-3-yl)butyric acid (1.65 g).
Workup
- filtrationThe zinc powder was filtered off
- washwashed with acetic acid
- customevaporated in vacuo
- additionTo the residue a saturated aqueous solution of sodium hydrogen carbonate (50 ml) was added
- extractionextracted with ethyl acetate (50 ml×2)
- washThe combined extracts were washed with a saturated aqueous solution of sodium chloride (50 ml)
- dry with materialdried over magnesium sulfate
- customevaporated in vacuo
- customThe residue was recrystallized from ethanol
Sources & evidence
- ORD record
- ord-b206540645e64503ac5f263ffa1aeedf
- Source dataset
- uspto-grants-1991_01
- Patent number
- US04985444
Reaction notes
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