Hydrazine hydrate (1:1) → 3-(3,4-dimethoxyphenyl)-4,5-dihydro-1H-pyrazol-5-one

HRID 855701Notes

Reaction equation

HRID 855701 reaction equation
C([O:3][C:4](=O)[CH2:5][C:6](=O)[C:7]1[CH:12]=[CH:11][C:10]([O:13][CH3:14])=[C:9]([O:15][CH3:16])[CH:8]=1)C.O.[NH2:20][NH2:21]>C(O)C>[CH3:16][O:15][C:9]1[CH:8]=[C:7]([C:6]2[CH2:5][C:4](=[O:3])[NH:21][N:20]=2)[CH:12]=[CH:11][C:10]=1[O:13][CH3:14]

Participants

4

Reactant 2

HCID 24654Hydrazine hydrate (1:1)HCID 2758465Ethyl 3,4-dimethoxybenzoylacetate

Product 1

HCID 152835193-(3,4-dimethoxyphenyl)-4,5-dihydro-1H-pyrazol-5-oneYield 60%

Reagents, catalysts & solvents 1

HCID 702EthanolSolvent

Procedure

To a solution of ethyl-3,4-dimethoxybenzoylacetate (1 g, 4 mmol), (Heterocycles 1979, 13, 239), in ethanol (5 ml) containing hydrazine hydrate (192 μl, 4 mmol) was stirred for 30 minutes at ambient temperature followed by 40 minutes being heated at reflux. After cooling at ambient temperature, the mixture was concentrated to half the volume and ether (10 ml) was added. After trituration, the solid was collected by filtration, washed with ether and dried under vacuum to give 3-(3,4-dimethoxyphenyl)-4,5-dihydro-1H-pyrazol-5-one (521 mg, 60%).

Workup

  1. waitfollowed by 40 minutes
  2. temperaturebeing heated
  3. temperatureat reflux
  4. temperatureAfter cooling at ambient temperature
  5. concentrationthe mixture was concentrated to half the volume and ether (10 ml)
  6. additionwas added
  7. filtrationAfter trituration, the solid was collected by filtration
  8. washwashed with ether
  9. customdried under vacuum

Sources & evidence

ORD record
ord-51a6435bf17b4dd4a8cd173812b11571
Source dataset
uspto-grants-2007_08
Patent number
US07262201B1

Reaction notes

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