p-Toluenesulfonic acid → 5-Hydroxy-1H-pyrazole-3-carboxylic acid methyl ester

HRID 1695377Notes

Reaction equation

HRID 1695377 reaction equation
[CH3:1][O:2][C:3](=[O:12])/[C:4](/[NH:10][NH2:11])=[CH:5]\[C:6](OC)=[O:7].C1(C)C=CC(S(O)(=O)=O)=CC=1>C1(C)C(C)=CC=CC=1>[CH3:1][O:2][C:3]([C:4]1[NH:10][N:11]=[C:6]([OH:7])[CH:5]=1)=[O:12]

Participants

4

Reactant 2

HCID 6101p-Toluenesulfonic acidHCID 55298578(E)-2-Hydrazino-but-2-enedioic acid dimethyl ester

Product 1

HCID 1784986025-Hydroxy-1H-pyrazole-3-carboxylic acid methyl esterYield 69.4%

Reagents, catalysts & solvents 1

HCID 7237O-XyleneSolvent

Procedure

To a solution of (E)-2-hydrazino-but-2-enedioic acid dimethyl ester (500 mg, 2.87 mmol) in xylene (10 mL) was added para-toluenesulfonic acid (45 mg, 0.24 mmol) and the resulting mixture heated at reflux for 4 h. After cooling to room temperature the mixture was stirred overnight and the resulting solid was filtered off and dried to afford the title compound (283 mg, 69%) as a white solid after trituration with dichloromethane. MS: m/e=141.1 [M+H]+.

Workup

  1. temperaturethe resulting mixture heated
  2. temperatureat reflux for 4 h
  3. filtrationthe resulting solid was filtered off
  4. customdried

Sources & evidence

ORD record
ord-d53b57aa740841bf8a551917fb077ad4
Source dataset
uspto-grants-2012_04
Patent number
US08163728B2

Reaction notes

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