Ethanol → 1-(2,4-Dichlorophenyl)-1H-pyrazol-4-ol

HRID 1632164Notes

Reaction equation

HRID 1632164 reaction equation
[Cl:1][C:2]1[CH:7]=[C:6]([Cl:8])[CH:5]=[CH:4][C:3]=1[NH:9][N:10]=[C:11](CCl)[CH:12]=[O:13].[OH-].[Na+].[CH2:18](O)C>O>[Cl:1][C:2]1[CH:7]=[C:6]([Cl:8])[CH:5]=[CH:4][C:3]=1[N:9]1[CH:18]=[C:12]([OH:13])[CH:11]=[N:10]1

Participants

5

Reactant 3

HCID 702Ethanol2×HCID 14798Sodium HydroxideHCID 88676496HCID 88676496, compound

Product 1

HCID 27639731-(2,4-Dichlorophenyl)-1H-pyrazol-4-olYield 87%

Reagents, catalysts & solvents 1

HCID 962WaterSolvent

Procedure

27.0 g of 3-chloropyruvaldehyde 2,4-dichlorophenylhydrazone is suspended in 100 ml of ethanol. To the suspension is added at room temperature 12 g of sodium hydroxide dissolved in 10 ml of water. After stirring the mixture for 2 hours ethanol is distilled off, and water is added to the resultant residue to dissolve it. Insolubles are removed by filtration, and the filtrate is neutralized with glacial acetic acid. The precipitate is recovered by filtration, washed with water and dried. Recrystallization from toluene results in 17.3 g of the subject compound in the yield of 87%. m.p. 148° to 149° C.

Workup

  1. distillationis distilled off
  2. additionwater is added to the resultant residue
  3. dissolutionto dissolve it
  4. customInsolubles are removed by filtration
  5. filtrationThe precipitate is recovered by filtration
  6. washwashed with water
  7. customdried
  8. customRecrystallization from toluene

Sources & evidence

ORD record
ord-b392bdc78d124f65a847bb049e6d9da6
Source dataset
uspto-grants-1984_10
Patent number
US04474775

Reaction notes

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