p-Toluenesulfonic acid → 5-(3-Methyl-4-nitro-phenyl)-2,4-dihydro-pyrazol-3-one

HRID 2243268Notes

Reaction equation

HRID 2243268 reaction equation
[CH3:1][C:2]1[CH:3]=[C:4]([C:11](=O)[CH2:12][C:13]([O:15]CC)=O)[CH:5]=[CH:6][C:7]=1[N+:8]([O-:10])=[O:9].O.[NH2:20][NH2:21].C1(C)C=CC(S(O)(=O)=O)=CC=1>C(O)C>[CH3:1][C:2]1[CH:3]=[C:4]([C:11]2[CH2:12][C:13](=[O:15])[NH:20][N:21]=2)[CH:5]=[CH:6][C:7]=1[N+:8]([O-:10])=[O:9]

Participants

5

Reactant 3

HCID 6101p-Toluenesulfonic acidHCID 24654Hydrazine hydrate (1:1)HCID 50999720Ethyl 3-(3-methyl-4-nitrophenyl)-3-oxopropanoate

Product 1

HCID 592103875-(3-Methyl-4-nitro-phenyl)-2,4-dihydro-pyrazol-3-oneYield 99.3%

Reagents, catalysts & solvents 1

HCID 702EthanolSolvent

Procedure

To an ethanol solution of ethyl 3-(3-methyl-4-nitro-phenyl)-3-oxo-propionate (3.0 g), hydrazine monohydrate (0.9 g) and a small amount of p-toluenesulfonic acid were added and the mixture was refluxed for 5 hours. After cooling, the solvent was distilled off under the reduced pressure and the obtained residue was purified by silica gel column chromatography to obtain 5-(3-methyl-4-nitro-phenyl)-2,4-dihydro-pyrazol-3-one (2.6 g). mp; 218-219° C.

Workup

  1. temperaturethe mixture was refluxed for 5 hours
  2. temperatureAfter cooling
  3. distillationthe solvent was distilled off under the reduced pressure
  4. customthe obtained residue was purified by silica gel column chromatography

Sources & evidence

ORD record
ord-cd380521baa74aa08fc17420e6503908
Source dataset
uspto-grants-2010_03
Patent number
US07674807B2

Reaction notes

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