Methyl acetoacetate → 2-Cyclohexyl-5-methyl-2,4-dihydro-pyrazol-3-one

HRID 915907Notes

Reaction equation

HRID 915907 reaction equation
[C:1]([O:7]C)(=O)[CH2:2][C:3]([CH3:5])=O.Cl.[CH:10]1([NH:16][NH2:17])[CH2:15][CH2:14][CH2:13][CH2:12][CH2:11]1.[OH-].[Na+]>>[CH:10]1([N:16]2[C:1](=[O:7])[CH2:2][C:3]([CH3:5])=[N:17]2)[CH2:15][CH2:14][CH2:13][CH2:12][CH2:11]1

Participants

4

Reactant 3

HCID 7757Methyl acetoacetateHCID 14798Sodium HydroxideHCID 207836Cyclohexylhydrazine hydrochloride

Product 1

HCID 101926052-Cyclohexyl-5-methyl-2,4-dihydro-pyrazol-3-oneYield 79%

Conditions

Temperature
120 °C

Procedure

A mixture of 14.5 ml (0.134 mol) of methyl acetoacetate and 20.2 g (0.134 mol) of cyclohexylhydrazine hydrochloride was stirred at 120° C. for 2 hours, and then cooled. The reaction mixture was neutralized with 30 ml of a 4M aqueous solution of sodium hydroxide, and extracted with ethyl acetate. The organic layer was washed with water and a saturated aqueous solution of sodium chloride, dried over anhydrous sodium sulfate, and distilled under reduced pressure to remove the solvent. Hexane was added to the residue, and precipitated crystals were collected by filtration to obtain 19.0 g (79%) of the captioned compound.

Workup

  1. temperaturecooled
  2. extractionextracted with ethyl acetate
  3. washThe organic layer was washed with water
  4. dry with materiala saturated aqueous solution of sodium chloride, dried over anhydrous sodium sulfate
  5. distillationdistilled under reduced pressure
  6. customto remove the solvent
  7. additionHexane was added to the residue
  8. customprecipitated crystals
  9. filtrationwere collected by filtration

Sources & evidence

ORD record
ord-2010d9491e664ed5ac81d1f1a3d96770
Source dataset
uspto-grants-2007_09
Patent number
US07268128B2

Reaction notes

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