Ethyl Acetoacetate → 2-(4-Methoxyphenyl)-5-methyl-2,4-dihydro-3H-pyrazol-3-one

HRID 1706366Notes

Reaction equation

HRID 1706366 reaction equation
[CH3:1][O:2][C:3]1[CH:8]=[CH:7][C:6]([NH:9][NH2:10])=[CH:5][CH:4]=1.C([O-])(=O)C.[Na+].[C:16](OCC)(=[O:21])[CH2:17][C:18]([CH3:20])=O>C(O)C.O>[CH3:1][O:2][C:3]1[CH:8]=[CH:7][C:6]([N:9]2[C:16](=[O:21])[CH2:17][C:18]([CH3:20])=[N:10]2)=[CH:5][CH:4]=1

Participants

6

Reactant 3

HCID 8868Ethyl AcetoacetateHCID 77023(4-Methoxyphenyl)hydrazineHCID 517045Sodium Acetate

Product 1

HCID 1247322-(4-Methoxyphenyl)-5-methyl-2,4-dihydro-3H-pyrazol-3-one

Reagents, catalysts & solvents 2

HCID 702EthanolSolventHCID 962WaterSolvent

Procedure

The starting material is obtained as follows: To the suspension of 2,700 g of p-methoxyphenylhydrazine in 24,600 ml of 50% aqueous ethanol, the solution of 1,411 g of sodium acetate in 3,000 ml of water is added while stirring under nitrogen at room temperature for 15 minutes, followed by 2,148 g of ethyl acetoacetate during 30 minutes at 25°-30°. The mixture is refluxed for 45 minutes, slowly cooled to 10° and stirred overnight. The precipitate formed is filtered off, washed twice with 2,000 ml of cold 50% aqueous ethanol each, and dissolved in 2,000 ml of boiling anhydrous ethanol. The solution is stirred at room temperature overnight, the precipitate formed filtered off and washed twice with 500 ml of cold ethanol, to yield the 1-(p-methoxyphenyl)-3-methyl-2-pyrazolin-5-one melting at 125°-128°.

Workup

  1. customThe starting material is obtained
  2. temperatureThe mixture is refluxed for 45 minutes
  3. temperatureslowly cooled to 10°
  4. stirringstirred overnight
  5. customThe precipitate formed
  6. filtrationis filtered off
  7. washwashed twice with 2,000 ml of cold 50% aqueous ethanol each, and
  8. dissolutiondissolved in 2,000 ml of boiling anhydrous ethanol
  9. stirringThe solution is stirred at room temperature overnight
  10. customthe precipitate formed
  11. filtrationfiltered off
  12. washwashed twice with 500 ml of cold ethanol

Sources & evidence

ORD record
ord-2d63b21c40534cd8a7ac3f83a49f90d4
Source dataset
uspto-grants-1980_06
Patent number
US04207317

Reaction notes

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