1,2-Dibromoethane → methyl 1-(2-bromoethyl)-3-nitro-1H-pyrazole-5-carboxylate

HRID 1431179Notes

Reaction equation

HRID 1431179 reaction equation
[N+:1]([C:4]1[NH:8][N:7]=[C:6]([C:9]([O:11][CH3:12])=[O:10])[CH:5]=1)([O-:3])=[O:2].C(=O)([O-])[O-].[K+].[K+].[Br:19][CH2:20][CH2:21]Br>CC(C)=O>[Br:19][CH2:20][CH2:21][N:7]1[C:6]([C:9]([O:11][CH3:12])=[O:10])=[CH:5][C:4]([N+:1]([O-:3])=[O:2])=[N:8]1

Participants

5

Reactant 3

HCID 78391,2-DibromoethaneHCID 11430Potassium CarbonateHCID 135452337methyl 3-nitro-1H-pyrazole-5-carboxylate

Product 1

HCID 66743273methyl 1-(2-bromoethyl)-3-nitro-1H-pyrazole-5-carboxylateYield 50.1%

Reagents, catalysts & solvents 1

HCID 180AcetoneSolvent

Procedure

To a solution of methyl 5-nitro-1H-pyrazole-3-carboxylate (5.97 g, 34.9 mmol) in acetone (100 mL) was added potassium carbonate (24.1 g, 174 mmol) and 1,2-dibromoethane (19.7 g, 9.02 ml, 105 mmol) and the resulting solution heated to reflux for 2 h and then stirred at room temperature overnight. The resulting mixture was filtered and concentrated and the residue purified by flash chromatography (silica gel, SF65-400 g, 20% to 70% ethyl acetate in hexanes) to give methyl 1-(2-bromoethyl)-3-nitro-1H-pyrazole-5-carboxylate (4.86 g, 50%) as a light yellow solid.

Workup

  1. temperaturethe resulting solution heated
  2. temperatureto reflux for 2 h
  3. filtrationThe resulting mixture was filtered
  4. concentrationconcentrated
  5. customthe residue purified by flash chromatography (silica gel, SF65-400 g, 20% to 70% ethyl acetate in hexanes)

Sources & evidence

ORD record
ord-60f5fdcc77144c789b6ab2cb43015b0e
Source dataset
uspto-grants-2015_01
Patent number
US08940741B2

Reaction notes

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