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

HRID 409389Notes

Reaction equation

HRID 409389 reaction equation
[CH2:1]([O:3][C:4](=[O:15])[CH2:5][C:6]1[C:7]([CH2:13][CH3:14])=[N:8][NH:9][C:10]=1[CH2:11][CH3:12])[CH3:2].[N+:16]([C:19]1[CH:26]=[CH:25][C:22]([CH2:23]Br)=[CH:21][CH:20]=1)([O-:18])=[O:17].C([O-])([O-])=O.[K+].[K+].O>C(#N)C>[CH2:1]([O:3][C:4](=[O:15])[CH2:5][C:6]1[C:7]([CH2:13][CH3:14])=[N:8][N:9]([CH2:23][C:22]2[CH:25]=[CH:26][C:19]([N+:16]([O-:18])=[O:17])=[CH:20][CH:21]=2)[C:10]=1[CH2:11][CH3:12])[CH3:2]

Participants

6

Reactant 4

HCID 962WaterHCID 11430Potassium CarbonateHCID 660114-Nitrobenzyl bromideHCID 57899303(3,5-diethyl-1H-pyrazol-4-yl)acetic acid ethyl ester

Product 1

HCID 68276573[3,5-diethyl-1-(4-nitro-benzyl)-1H-pyrazol-4-yl]acetic acid ethyl esterYield 69.5%

Reagents, catalysts & solvents 1

HCID 6342AcetonitrileSolvent

Procedure

To a solution of (3,5-diethyl-1H-pyrazol-4-yl) acetic acid ethyl ester (10.95 g, 52.1 mmol) and 4-nitrobenzyl bromide (14.625 g, 68 mmol) in acetonitrile (110 mL) is added K2CO3 (10.80 g, 78.1 mmol) and the mixture is stirred for 48 hours 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. The residue is purified by MPLC with ethyl acetate/cyclohexane to yield 12.50 g [3,5-diethyl-1-(4-nitro-benzyl)-1H-pyrazol-4-yl]acetic acid ethyl ester (ESI mass spectrum: [M+H]+=346; Retention time HPLC: 1.42 min (method B)). b) To a solution of [3,5-diethyl-1-(4-nitro-benzyl)-1H-pyrazol-4-yl]acetic acid ethyl ester (6.66 g, 19.3 mmol) in methanol (500 mL) is added Raney nickel (500 mg) and the mixture is hydrogenated at 50 psi and room temperature. The catalyst is filtered off and the filtrate is concentrated under reduced pressure to yield 4.38 g of the title compound (ESI mass spectrum: [M+H]+=316; Retention time HPLC: 1.09 min (method B)).

Workup

  1. extractionextracted twice with ethyl acetate
  2. dry with materialThe organic phase is dried over MgSO4
  3. customevaporated under reduced pressure
  4. customThe residue is purified by MPLC with ethyl acetate/cyclohexane

Sources & evidence

ORD record
ord-de1aea9df4ea4e84b0c86da58a48b779
Source dataset
uspto-grants-2014_06
Patent number
US08759386B2

Reaction notes

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