Potassium Carbonate → 1-(4-methoxy-benzyl)-4-nitro-1H-pyrazole-3-carboxylic acid ethyl ester
Reaction equation
[CH2:1]([O:3][C:4]([C:6]1[C:10]([N+:11]([O-:13])=[O:12])=[CH:9][NH:8][N:7]=1)=[O:5])[CH3:2].C([O-])([O-])=O.[K+].[K+].[CH3:20][O:21][C:22]1[CH:29]=[CH:28][C:25]([CH2:26]Cl)=[CH:24][CH:23]=1>CC#N>[CH2:1]([O:3][C:4]([C:6]1[C:10]([N+:11]([O-:13])=[O:12])=[CH:9][N:8]([CH2:26][C:25]2[CH:28]=[CH:29][C:22]([O:21][CH3:20])=[CH:23][CH:24]=2)[N:7]=1)=[O:5])[CH3:2]Participants
5
Procedure
To a solution of 4-nitro-1H-pyrazole-3-carboxylic acid ethyl ester (8.8 g, 47.5 mmol) in MeCN (100 ml) was added K2CO3 (7.9 g, 57.0 mmol) followed by 4-methoxybenzyl chloride (7.1 ml, 52.3 mmol) and the mixture stirred at ambient temperature for 20 hours. The mixture was evaporated in vacuo, the residue partitioned between EtOAc and 2M aqueous hydrochloric acid and the organic portion washed with saturated aqueous sodium hydrogen carbonate, dried (MgSO4) and evaporated in vacuo. The residue was purified by flash column chromatography [SiO2, EtOAc-hexane (1:4)] to give 1-(4-methoxy-benzyl)-4-nitro-1H-pyrazole-3-carboxylic acid ethyl ester (11 g) as a colourless gum.
Workup
- customThe mixture was evaporated in vacuo
- customthe residue partitioned between EtOAc and 2M aqueous hydrochloric acid
- washthe organic portion washed with saturated aqueous sodium hydrogen carbonate
- dry with materialdried (MgSO4)
- customevaporated in vacuo
- customThe residue was purified by flash column chromatography [SiO2, EtOAc-hexane (1:4)]
Sources & evidence
- ORD record
- ord-c67e892fbbc04a88af04094937885cf6
- Source dataset
- uspto-grants-2011_07
- Patent number
- US07977477B2
Reaction notes
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