Water → [3,5-Dimethyl-1-(4-nitro-benzyl)-1H-pyrazol-4-yl]-acetic acid methyl ester

HRID 409387Notes

Reaction equation

HRID 409387 reaction equation
[CH3:1][O:2][C:3](=[O:12])[CH2:4][C:5]1[C:6]([CH3:11])=[N:7][NH:8][C:9]=1[CH3:10].[N+:13]([C:16]1[CH:23]=[CH:22][C:19]([CH2:20]Br)=[CH:18][CH:17]=1)([O-:15])=[O:14].C([O-])([O-])=O.[K+].[K+].O>C(#N)C>[CH3:1][O:2][C:3](=[O:12])[CH2:4][C:5]1[C:9]([CH3:10])=[N:8][N:7]([CH2:20][C:19]2[CH:22]=[CH:23][C:16]([N+:13]([O-:15])=[O:14])=[CH:17][CH:18]=2)[C:6]=1[CH3:11]

Participants

6

Reactant 4

HCID 962WaterHCID 11430Potassium CarbonateHCID 660114-Nitrobenzyl bromideHCID 7131483methyl 2-(3,5-dimethyl-1H-pyrazol-4-yl)acetate

Product 1

HCID 66707610[3,5-Dimethyl-1-(4-nitro-benzyl)-1H-pyrazol-4-yl]-acetic acid methyl esterYield 119.5%

Reagents, catalysts & solvents 1

HCID 6342AcetonitrileSolvent

Procedure

To a solution of (3,5-dimethyl-1H-pyrazol-4-yl)acetic acid methyl ester (3.90 g, 23 mmol) and 4-nitrobenzyl bromide (4.60 g, 20.7 mmol) in acetonitrile is added K2CO3 (2.76 g, 19.9 mmol) and the mixture is stirred for one hour at room temperature. The reaction mixture is poured into water and extracted twice with ethyl acetate. The organic phase is dried over MgSO4 and evaporated under reduced pressure. To yield 7.50 g of [3,5-Dimethyl-1-(4-nitro-benzyl)-1H-pyrazol-4-yl]-acetic acid methyl ester (ESI mass spectrum: [M+H]+=304). b) To a solution of [3,5-dimethyl-1-(4-nitrobenzyl)-1H-pyrazol-4-yl]acetic acid methyl ester (3.90 g, 10.3 mmol) in methanol (10 mL) is added 10% palladium on charcoal (500 mg) and the mixture is hydrogenated. The catalyst is filtered off and the filtrate is concentrated under reduced pressure. The mixture is purified via preparative reversed phase HPLC (gradient of methanol in water+0.1% NH3) to yield 1.18 g of the title compound (ESI mass spectrum: [M+H]+=274; Retention time HPLC: 2.13 min (method A))

Workup

  1. extractionextracted twice with ethyl acetate
  2. dry with materialThe organic phase is dried over MgSO4
  3. customevaporated under reduced pressure

Sources & evidence

ORD record
ord-5e4ca99c69d04313a5690fa5e9985eea
Source dataset
uspto-grants-2014_06
Patent number
US08759386B2

Reaction notes

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