Phenylhydrazine → 5-Methyl-1-phenyl-4,5-dihydro-1H-pyrazol-3-amine

HRID 2198972Notes

Reaction equation

HRID 2198972 reaction equation
[Na].[C:2]1([NH:8][NH2:9])[CH:7]=[CH:6][CH:5]=[CH:4][CH:3]=1.[C:10](#[N:14])/[CH:11]=[CH:12]/[CH3:13]>C(O)C>[NH2:14][C:10]1[CH2:11][CH:12]([CH3:13])[N:8]([C:2]2[CH:7]=[CH:6][CH:5]=[CH:4][CH:3]=2)[N:9]=1

Participants

5

Reactant 3

HCID 7516PhenylhydrazineHCID 637921CrotononitrileHCID 5360545Sodium

Product 1

HCID 155806655-Methyl-1-phenyl-4,5-dihydro-1H-pyrazol-3-amine

Reagents, catalysts & solvents 1

HCID 702EthanolSolvent2×

Procedure

A 2.0 g. amount of sodium metal is dissolved in 200 ml. of absolute ethanol, then 32.4 g. of phenylhydrazine in 50 ml. of ethanol is added followed in 10 minutes by 20.1 g. of crotononitrile. The reaction mixture is refluxed for 5 hours. Most of the ethanol is removed in vacuo, water is added and the product is collected by filtration. The solid is dissolved in dichloromethane. This solution is passed through a short column of a hydrous magnesium silicate. The column effluent is then refluxed on a steam bath with the gradual addition of hexane to crystallize a product. The product is collected and recrystallized from acetone-hexane to give 26.9 g. of the product of the Example as colorless prisms, m.p. 103.5°-106° C.

Workup

  1. temperatureThe reaction mixture is refluxed for 5 hours
  2. customMost of the ethanol is removed in vacuo, water
  3. additionis added
  4. filtrationthe product is collected by filtration
  5. dissolutionThe solid is dissolved in dichloromethane
  6. temperatureThe column effluent is then refluxed on a steam bath with the gradual addition of hexane
  7. customto crystallize a product
  8. customThe product is collected
  9. customrecrystallized from acetone-hexane
  10. customto give 26.9 g

Sources & evidence

ORD record
ord-45142eb46c5147ba84a0fb4fcd41412c
Source dataset
uspto-grants-1982_11
Patent number
US04360680

Reaction notes

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