1H-Indazole-3-carboxylic acid, 1-methyl- → 1-(1-Methyl-1H-indazol-3-yl)ethan-1-one
Reaction equation
[CH3:1][Li].[CH3:3][N:4]1[C:12]2[C:7](=[CH:8][CH:9]=[CH:10][CH:11]=2)[C:6]([C:13]([OH:15])=O)=[N:5]1>C1COCC1>[CH3:3][N:4]1[C:12]2[C:7](=[CH:8][CH:9]=[CH:10][CH:11]=2)[C:6]([C:13](=[O:15])[CH3:1])=[N:5]1Participants
4
Reactant 2
Product 1
Reagents, catalysts & solvents 1
Procedure
Methyl lithium (1.58M solution in ether; 13.8 ml) was added dripwise to a stirred, cold (-60°) solution of 1-methyl-1H-indazole-3-carboxylic acid (1.77 g) in dry THF (60 ml) under nitrogen and stirring was continued while warming to 0° over 2 h. The reaction mixture was quenched with saturated ammonium chloride solution (50 ml), and the layers were separated. The aqueous layer was further extracted with dichloromethane (2×50 ml ) and the combined organic layers were washed with brine (2×50 ml ), dried and evaporated in vacuo. The residual solid (1.8 g) was purified by FCC eluting with System B (1:4) to give the title compound (1.3 g, m.p. 86°-88°.
Workup
- temperaturewhile warming to 0° over 2 h
- customThe reaction mixture was quenched with saturated ammonium chloride solution (50 ml)
- customthe layers were separated
- extractionThe aqueous layer was further extracted with dichloromethane (2×50 ml )
- washthe combined organic layers were washed with brine (2×50 ml )
- customdried
- customevaporated in vacuo
- customThe residual solid (1.8 g) was purified by FCC
- washeluting with System B (1:4)
Sources & evidence
- ORD record
- ord-f6d7326975814d9a9f8235ae3a430693
- Source dataset
- uspto-grants-1991_05
- Patent number
- US05019586
Reaction notes
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