Acrylonitrile → 1-(3-Fluorophenyl)-4,5-dihydro-1H-pyrazol-3-amine

HRID 544635Notes

Reaction equation

HRID 544635 reaction equation
[Na].Cl.[F:3][C:4]1[CH:5]=[C:6]([NH:10][NH2:11])[CH:7]=[CH:8][CH:9]=1.[C:12](#[N:15])[CH:13]=[CH2:14]>C(O)C>[NH2:15][C:12]1[CH2:13][CH2:14][N:10]([C:6]2[CH:7]=[CH:8][CH:9]=[C:4]([F:3])[CH:5]=2)[N:11]=1

Participants

5

Reactant 3

HCID 7855AcrylonitrileHCID 27239143-Fluorophenylhydrazine hydrochlorideHCID 5360545Sodium

Product 1

HCID 133095101-(3-Fluorophenyl)-4,5-dihydro-1H-pyrazol-3-amine

Reagents, catalysts & solvents 1

HCID 702EthanolSolvent

Procedure

A 1.38 g. amount of sodium metal is dissolved in 150 ml. of absolute ethanol, then 8.1 g. of m-fluorophenylhydrazine hydrochloride is added followed in 15 minutes by 2.75 g. of acrylonitrile. The reaction mixture is refluxed for 5 hours, then is evaporated to dryness in vacuo. Water is added and the separated solid is collected by filtration. The solid is dissolved in dichloromethane and the solution is passed through a short column of a hydrous magnesium silicate. The effluent is heated to reflux on a steam bath and hexane is added to precipitate a product. The solid is collected, dissolved in acetone, treated with activated charcoal and filtered. Hexane is added to the filtrate to crystallize 2.95 g. of the product of the Example as off-white needles, m.p. 146°-147° C.

Workup

  1. temperatureThe reaction mixture is refluxed for 5 hours
  2. customis evaporated to dryness in vacuo
  3. additionWater is added
  4. filtrationthe separated solid is collected by filtration
  5. dissolutionThe solid is dissolved in dichloromethane
  6. temperatureThe effluent is heated
  7. temperatureto reflux on a steam bath
  8. additionhexane is added
  9. customto precipitate a product
  10. customThe solid is collected
  11. dissolutiondissolved in acetone
  12. additiontreated with activated charcoal
  13. filtrationfiltered
  14. additionHexane is added to the filtrate
  15. customto crystallize 2.95 g

Sources & evidence

ORD record
ord-6e13f13607604cd9a08961b0f5ea2029
Source dataset
uspto-grants-1984_05
Patent number
US04451479

Reaction notes

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