HCID 178499180, compound → HCID 178499176, compound

HRID 1951475Notes

Reaction equation

HRID 1951475 reaction equation
[CH3:1][O:2][C:3]([C:5]1[C:9]([N+:10]([O-])=O)=[CH:8][NH:7][N:6]=1)=[O:4].N#N.[H][H]>[Pd].C(O)C>[CH3:1][O:2][C:3]([C:5]1[C:9]([NH2:10])=[CH:8][NH:7][N:6]=1)=[O:4]

Participants

5

Reactant 2

HCID 178499180HCID 178499180, compoundHCID 178514468HCID 178514468, compound

Product 1

HCID 178499176HCID 178499176, compoundYield 98.9%

Reagents, catalysts & solvents 2

HCID 23938PalladiumCatalystHCID 702EthanolSolvent

Conditions

Temperature
29 °C

Procedure

A 20 L reaction vessel equipped with a digital thermometer and stirrer was charged with palladium on carbon (10% wet paste, 0.170 Kg, 0.14 wt) under nitrogen. In a separate vessel a slurry of 4-nitro-1H-pyrazole-3-carboxylic acid methyl ester (1.210 Kg, 7.07 mol, 1 wt) in ethanol (12.10 L, 10 vol) was warmed to 30 to 35° C. to effect dissolution and the solution added to the catalyst under nitrogen. Following a nitrogen-hydrogen purge sequence an atmosphere of hydrogen was introduced and the reaction mixture maintained at 28 to 30° C. until reaction completion (5 to 10 hours) was noted by 1H NMR analysis (d6-DMSO). Following a purge cycle, the reaction mixture under nitrogen was filtered and the liquors concentrated under reduced pressure to give 4-amino-1H-pyrazole-3-carboxylic acid methyl ester (0.987 Kg, 98.9%).

Workup

  1. customA 20 L reaction vessel
  2. customequipped with a digital thermometer and stirrer
  3. dissolutiondissolution
  4. additionthe solution added to the catalyst under nitrogen
  5. custompurge sequence an atmosphere of hydrogen
  6. additionwas introduced
  7. filtrationthe reaction mixture under nitrogen was filtered
  8. concentrationthe liquors concentrated under reduced pressure

Sources & evidence

ORD record
ord-4663e7d4538c4341b959488ed6af0b68
Source dataset
uspto-grants-2013_03
Patent number
US08404718B2

Reaction notes

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