Methanol → 1H-Pyrazole-3-carboxylic acid, 4-nitro-, methyl ester

HRID 606502Notes

Reaction equation

HRID 606502 reaction equation
S(Cl)(Cl)=O.[N+:5]([C:8]1[C:9]([C:13]([OH:15])=[O:14])=[N:10][NH:11][CH:12]=1)([O-:7])=[O:6].[CH3:16]O>>[N+:5]([C:8]1[CH:12]=[N:11][NH:10][C:9]=1[C:13]([O:15][CH3:16])=[O:14])([O-:7])=[O:6]

Participants

4

Reactant 3

HCID 887MethanolHCID 24386Thionyl ChlorideHCID 178524956HCID 178524956, compound

Product 1

HCID 12767041H-Pyrazole-3-carboxylic acid, 4-nitro-, methyl esterYield 82%

Procedure

Thionyl chloride (9.2 mL) was added dropwise to a solution of 4-nitro-1H-pyrazole-3-carboxylic acid (19.77 g, 125.9 mmol) in methanol (200 mL) at 0° C. The reaction mixture was stirred at room temperature overnight, and the solvent was evaporated under reduced pressure. Water was added to the residue, and the mixture was extracted with ethyl acetate. The organic layer was washed with saturated aqueous sodium hydrogencarbonate solution and saturated brine, dried and concentrated. The obtained crude crystals were washed with diisopropyl ether to give methyl 4-nitro-1H-pyrazole-5-carboxylate (17.8 g, 82%).

Workup

  1. customthe solvent was evaporated under reduced pressure
  2. additionWater was added to the residue
  3. extractionthe mixture was extracted with ethyl acetate
  4. washThe organic layer was washed with saturated aqueous sodium hydrogencarbonate solution and saturated brine
  5. customdried
  6. concentrationconcentrated
  7. customThe obtained crude crystals
  8. washwere washed with diisopropyl ether

Sources & evidence

ORD record
ord-f2f45aee289a4b73b5493a498eec2390
Source dataset
uspto-grants-2011_03
Patent number
US07915267B2

Reaction notes

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