Sodium hydride → methyl 2-(4-bromo-1H-pyrazol-1-yl)propanoate
Reaction equation
[H-].[Na+].[Br:3][CH:4]1[CH:8]=[N:7][N:6]=[CH:5]1.[CH3:9][O:10][C:11](=[O:15])[CH:12](Cl)[CH3:13]>CN(C=O)C>[CH3:9][O:10][C:11](=[O:15])[CH:12]([N:6]1[CH:5]=[C:4]([Br:3])[CH:8]=[N:7]1)[CH3:13]Participants
5
Reactant 3
Product 1
Reagents, catalysts & solvents 1
Procedure
Sodium hydride (0.12 g, 4.9 mmol) was added to a solution of 4-bromo-4H-pyrazole (0.60 g, 4.1 mmol) in DMF (10 mL). After stirring for 10 minutes, a solution of 2-chloro-propionic acid methyl ester in DMF (4 mL) was added. After stirring for 4 hours, the reaction was partitioned between ethyl acetate and water. The phases were separated and the aqueous phase was extracted with ethyl acetate. The combined organic phases were dried over MgSO4 and concentrated by rotary evaporation. The residue was purified by silica gel chromatography using gradient elution of ethyl acetate and hexanes to afford 2-(4-bromo-pyrazol-1-yl)-propionic acid methyl ester (733 mg, 77%).
Workup
- stirringAfter stirring for 4 hours
- customthe reaction was partitioned between ethyl acetate and water
- customThe phases were separated
- extractionthe aqueous phase was extracted with ethyl acetate
- dry with materialThe combined organic phases were dried over MgSO4
- concentrationconcentrated by rotary evaporation
- customThe residue was purified by silica gel chromatography
- washelution of ethyl acetate and hexanes
Sources & evidence
- ORD record
- ord-918514ca1c454bcd8dffa70e64e6382c
- Source dataset
- uspto-grants-2010_12
- Patent number
- US07858643B2
Reaction notes
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