HCID 178469978, compound → HCID 178469977, compound

HRID 443492Notes

Reaction equation

HRID 443492 reaction equation
[OH:1][C:2]1[N:6]([C:7]2[CH:12]=[CH:11][CH:10]=[CH:9][C:8]=2[N+:13]([O-])=O)[N:5]=[CH:4][C:3]=1[C:16]([O:18][CH2:19][CH3:20])=[O:17]>CO.[Pd]>[NH2:13][C:8]1[CH:9]=[CH:10][CH:11]=[CH:12][C:7]=1[N:6]1[C:2]([OH:1])=[C:3]([C:16]([O:18][CH2:19][CH3:20])=[O:17])[CH:4]=[N:5]1

Participants

4

Reactant 1

HCID 178469978HCID 178469978, compound

Product 1

HCID 178469977HCID 178469977, compoundYield 69.2%

Reagents, catalysts & solvents 2

HCID 23938PalladiumCatalystHCID 887MethanolSolvent

Procedure

126.3 g of 5-hydroxy-1-(2-nitrophenyl)-1H-pyrazole-4-carboxylic acid, ethyl ester is dissolved in 1.6 liter methanol and 1.2 g Pd/C (10%) are added and hydrogenation is performed until H2 -uptake is finished (12 hours). After filtration the solvent is distilled off and the crystalline residue is recrystallized from dimethylformamide/ethanol to yield 78 g of 1-(2-aminophenyl)-5-hydroxy-1H-pyrazole-4-carboxylic acid, ethyl ester as white powder having a melting point of 151°-154° C.

Workup

  1. custom(12 hours)
  2. filtrationAfter filtration the solvent
  3. distillationis distilled off
  4. customthe crystalline residue is recrystallized from dimethylformamide/ethanol

Sources & evidence

ORD record
ord-bc7311dbac1a4938810fb29dfe910d73
Source dataset
uspto-grants-1981_04
Patent number
US04260751

Reaction notes

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