Methanol → methyl 3-nitro-1H-pyrazole-5-carboxylate

HRID 550613Notes

Reaction equation

HRID 550613 reaction equation
[N+:1]([C:4]1[NH:8][N:7]=[C:6]([C:9]([OH:11])=[O:10])[CH:5]=1)([O-:3])=[O:2].S(Cl)(Cl)=O.[CH3:16]O>>[CH3:16][O:10][C:9]([C:6]1[CH:5]=[C:4]([N+:1]([O-:3])=[O:2])[NH:8][N:7]=1)=[O:11]

Participants

4

Reactant 3

HCID 887MethanolHCID 24386Thionyl ChlorideHCID 862226845-Nitro-1H-pyrazole-3-carboxylic acid

Product 1

HCID 135452337methyl 3-nitro-1H-pyrazole-5-carboxylateYield 95.7%

Procedure

5-Nitro-3-pyrazol carboxylic acid (21.44 g, 136.5 mmol) is dissolved in dry methanol (200 mL). Then, thionyl chloride (9.9 mL, 136.5 mmol) is added slowly in a drop wise manner at RT. The reaction mixture is heated over night under reflux and under argon atmosphere. After cooling down, the solvent is evaporated under vacuum and the crude material is heated with boiling hexane (200 ml). After cooling down and removal of the hexane, the material is washed two times with 200 ml pentane. Then, the solvent is removed and the product is dried under vacuum to give 5-nitro-3-pyrazole-carboxylic acid methyl ester (22.35 g, 95.7%).

Workup

  1. temperatureThe reaction mixture is heated over night
  2. temperatureunder reflux and under argon atmosphere
  3. temperatureAfter cooling down
  4. customthe solvent is evaporated under vacuum
  5. temperaturethe crude material is heated with boiling hexane (200 ml)
  6. temperatureAfter cooling down
  7. customremoval of the hexane
  8. washthe material is washed two times with 200 ml pentane
  9. customThen, the solvent is removed
  10. customthe product is dried under vacuum

Sources & evidence

ORD record
ord-f01c987101f44a34b87f8c4e130cf7dd
Source dataset
uspto-grants-2011_05
Patent number
US07947689B2

Reaction notes

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