Hydrochloric Acid → 1-(3,4-Dichlorophenyl)-1H-pyrazol-3-amine

HRID 1958879Notes

Reaction equation

HRID 1958879 reaction equation
[Na].Cl.[Cl:3][C:4]1[CH:5]=[C:6]([NH:11][NH2:12])[CH:7]=[CH:8][C:9]=1[Cl:10].[CH2:13]([O:15][C:16](=[CH2:19])[C:17]#[N:18])[CH3:14].Cl.[OH-].[Na+:22]>C(O)C.O>[O-:15][CH2:13][CH3:14].[Na+:22].[Cl:3][C:4]1[CH:5]=[C:6]([N:11]2[CH:19]=[CH:16][C:17]([NH2:18])=[N:12]2)[CH:7]=[CH:8][C:9]=1[Cl:10]

Participants

9

Reactant 5

HCID 313Hydrochloric AcidHCID 14798Sodium HydroxideHCID 3084323(3,4-Dichlorophenyl)hydrazine monohydrochlorideHCID 5360545SodiumHCID 123499402-Ethoxyprop-2-enenitrile

Product 2

HCID 2723922Sodium ethoxideHCID 234642861-(3,4-Dichlorophenyl)-1H-pyrazol-3-amineYield 88%

Reagents, catalysts & solvents 2

HCID 702EthanolSolvent2×HCID 962WaterSolvent

Procedure

A solution of sodium ethoxide in ethanol was prepared by dissolving sodium (0.5 g, 21.9 mmol) in ethanol (25 ml) in a dry nitrogen atmosphere and 3,4-dichlorophenylhydrazine hydrochloride (1.85 g, 8 mmol) was added. The mixture was warmed to reflux for 45 min. with stirring, then cooled to room temperature and ethoxyacrylonitrile (1.4 g, 14 mmol) added and warmed again to reflux for 24 hours. The reaction mixture was cooled to room temperature and followed by addition of water (7 ml) and 6N HCl to adjust the pH to ≈2. The resulting aqueous-ethanolic solution was stirred at room temperature for 3 hours, treated with 10% aq. NaOH to a pH 7-8 and stirred overnight. A red colour solid appeared and it was filtered, washed with water and dried to give 1-(3,4-dichlorophenyl)-1H-pyrazol-3-amine (1.57 g, 88% yield)

Workup

  1. additionwas added
  2. temperatureThe mixture was warmed
  3. temperatureto reflux for 45 min.
  4. temperaturewarmed again
  5. temperatureto reflux for 24 hours
  6. temperatureThe reaction mixture was cooled to room temperature
  7. stirringThe resulting aqueous-ethanolic solution was stirred at room temperature for 3 hours
  8. stirringstirred overnight
  9. filtrationit was filtered
  10. washwashed with water
  11. customdried

Sources & evidence

ORD record
ord-148cadf2b71f4e98a158e9d4e7c4dcc5
Source dataset
uspto-grants-2013_04
Patent number
US08410159B2

Reaction notes

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