Sodium hydride → tert-Butyl 2-(3-nitro-1H-pyrazol-1-yl)acetate

HRID 545988Notes

Reaction equation

HRID 545988 reaction equation
[N+:1]([C:4]1[CH:8]=[CH:7][NH:6][N:5]=1)([O-:3])=[O:2].[H-].[Na+].[C:11]([O:15][C:16](=[O:19])[CH2:17]Br)([CH3:14])([CH3:13])[CH3:12]>CN(C)C=O>[C:11]([O:15][C:16](=[O:19])[CH2:17][N:6]1[CH:7]=[CH:8][C:4]([N+:1]([O-:3])=[O:2])=[N:5]1)([CH3:14])([CH3:13])[CH3:12]

Participants

5

Reactant 3

HCID 24758Sodium hydrideHCID 79177tert-Butyl bromoacetateHCID 178526745HCID 178526745, compound

Product 1

HCID 66712097tert-Butyl 2-(3-nitro-1H-pyrazol-1-yl)acetateYield 77.2%

Reagents, catalysts & solvents 1

HCID 6228DimethylformamideSolvent

Procedure

To a solution of 3-Nitro-1H-pyrazole (1.00 g, 8.84 mmol) in anhydrous N,N-dimethylformamide (20 mL), a 60% dispersion of sodium hydride in mineral oil (390 mg, 9.73 mmol) was added while stirring under nitrogen. After the effervescence ceased and the mixture was stirred for additional 1 h, tert-butyl-bromoacetate (1.44 mL, 9.73 mmol) was added. The mixture was continued to stir under nitrogen for an additional 2 h. The solvent was removed in vacuo and purification by ISCO flash column chromatography (Teledyne Isco RediSep Flash Column 40 g; 0% ethyl acetate/hexanes to 50% ethyl acetate/hexanes, 30 min) afforded (3-nitro-pyrazol-1-yl)-acetic acid tert-butyl ester (1.55 g, 77%) as a white powder. H1-NMR (400 MHz, CDCl3) δ: 1.42 (9H, s), 4.86 (2H, s), 6.87 (1H, d, J=2.4 Hz), 7.54 (1H, d, J=2.3 Hz).

Workup

  1. stirringthe mixture was stirred for additional 1 h
  2. stirringto stir under nitrogen for an additional 2 h
  3. customThe solvent was removed in vacuo and purification by ISCO flash column chromatography (Teledyne Isco RediSep Flash Column 40 g; 0% ethyl acetate/hexanes to 50% ethyl acetate/hexanes, 30 min)

Sources & evidence

ORD record
ord-b1f9fea6ac2a4765bd71101bdc3b5d23
Source dataset
uspto-grants-2011_05
Patent number
US07935699B2

Reaction notes

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