methyl 3-nitro-1H-pyrazole-5-carboxylate → HCID 178498460, compound

HRID 270924Notes

Reaction equation

HRID 270924 reaction equation
[CH3:1][O:2][C:3]([C:5]1[CH:9]=[C:8]([N+:10]([O-])=O)[NH:7][N:6]=1)=[O:4]>C(O)(=O)C.O1CCCC1.[Pd]>[CH3:1][O:2][C:3]([C:5]1[CH:9]=[C:8]([NH2:10])[NH:7][N:6]=1)=[O:4]

Participants

5

Reactant 1

HCID 135452337methyl 3-nitro-1H-pyrazole-5-carboxylate

Product 1

HCID 178498460HCID 178498460, compoundYield 85.4%

Reagents, catalysts & solvents 3

HCID 23938PalladiumCatalystHCID 176Acetic AcidSolventHCID 8028TetrahydrofuranSolvent

Procedure

10.25 g (60 mmol) of 5-nitro-1H-pyrazole-3-carboxylic acid methyl ester was dissolved in 75 mL of acetic acid (AcOH) and 75 mL of tetrahydrofuran (THF). After a vacuum and argon cycle, 2.05 g (20% weight) of palladium on carbon (Pd/C 10 wt %) was added, the mixture was degassed again and filled with hydrogen from a balloon. The reaction mixture was stirred at rt under hydrogen atmosphere for 2 days. Analysis by thin layer chromatography (TLC) showed complete conversion of starting material to product. The mixture was then concentrated, the resulting purple colored oil was taken in 300 mL of ether, the finely dispersed purple impurity was filtered off, and the ether filtrate was evaporated to give 7.23 g (85% yield) of 5-amino-1H-pyrazole-3-carboxylic acid methyl ester as an off-white solid as indicated by 1H NMR; whose structure was confirmed using 1H NMR.

Workup

  1. customthe mixture was degassed again
  2. additionfilled with hydrogen from a balloon
  3. concentrationThe mixture was then concentrated
  4. filtrationthe finely dispersed purple impurity was filtered off
  5. customthe ether filtrate was evaporated

Sources & evidence

ORD record
ord-64f9b570f5094af5ac49c81562ef11f3
Source dataset
uspto-grants-2008_11
Patent number
US07449488B2

Reaction notes

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