Water → 5-Ethoxy-2,4-dihydro-2-methyl-3H-pyrazol-3-one

HRID 1735013Notes

Reaction equation

HRID 1735013 reaction equation
[CH3:1][NH:2][NH2:3].[CH2:4]([O:6][C:7](OCC)=[CH:8][C:9]([O:11]CC)=O)[CH3:5].O.S(=O)(=O)(O)O>C(O)C.[Cl-].[Na+].O>[CH2:4]([O:6][C:7]1[CH2:8][C:9](=[O:11])[N:2]([CH3:1])[N:3]=1)[CH3:5]

Participants

7

Reactant 4

HCID 962WaterHCID 1118Sulfuric AcidHCID 6061MethylhydrazineHCID 1693882-Propenoic acid, 3,3-diethoxy-, ethyl ester

Product 1

HCID 194368075-Ethoxy-2,4-dihydro-2-methyl-3H-pyrazol-3-oneYield 42.5%

Reagents, catalysts & solvents 2

HCID 702EthanolSolventHCID 57417360Sodium chloride; waterSolvent

Procedure

Methylhydrazine (2.6 g, 0.056 mole) was added to a solution of ethyl 3,3-diethoxyacrylate (10.0 g, 0.053 mole) in ethanol (50 mL) and the mixture was heated and held at reflux for 18 hours. After cooling, water, saturated brine, and 3 mL of concentrated sulfuric acid were added; and the product was extracted with ethyl acetate. The combined extracts were dried with magnesium sulfate, filtered and concentrated in vacuo. Purification by chromatography on silica gel using ethyl acetate/cyclohexane gave 5-ethoxy-2,4-dihydro-2-methyl-3H-pyrazol-3-one (3.2 g, 42% yield) as a white solid, mp=79°-80° C.

Workup

  1. temperaturethe mixture was heated
  2. temperatureat reflux for 18 hours
  3. temperatureAfter cooling
  4. extractionand the product was extracted with ethyl acetate
  5. dry with materialThe combined extracts were dried with magnesium sulfate
  6. filtrationfiltered
  7. concentrationconcentrated in vacuo
  8. customPurification by chromatography on silica gel

Sources & evidence

ORD record
ord-f095f249f248418799d777db1de62de0
Source dataset
uspto-grants-1996_07
Patent number
US05536701

Reaction notes

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