4-Fluorophenylhydrazine hydrochloride → Ethyl 1-(4-fluorophenyl)-3-[4-(methylthio)phenyl]pyrazole-5-carboxylate

HRID 654779Notes

Reaction equation

HRID 654779 reaction equation
[CH3:1][S:2][C:3]1[CH:8]=[CH:7][C:6]([C:9](=O)[CH2:10][C:11](=O)[C:12]([O:14][CH2:15][CH3:16])=[O:13])=[CH:5][CH:4]=1.Cl.[F:20][C:21]1[CH:26]=[CH:25][C:24]([NH:27][NH2:28])=[CH:23][CH:22]=1>C(O)C.O1CCOCC1>[F:20][C:21]1[CH:26]=[CH:25][C:24]([N:27]2[C:11]([C:12]([O:14][CH2:15][CH3:16])=[O:13])=[CH:10][C:9]([C:6]3[CH:7]=[CH:8][C:3]([S:2][CH3:1])=[CH:4][CH:5]=3)=[N:28]2)=[CH:23][CH:22]=1

Participants

5

Reactant 2

HCID 699814-Fluorophenylhydrazine hydrochlorideHCID 10539688Ethyl 4-[4-(methylthio)phenyl]-2,4-dioxobutanoate

Product 1

HCID 10498473Ethyl 1-(4-fluorophenyl)-3-[4-(methylthio)phenyl]pyrazole-5-carboxylateYield 8.2%

Reagents, catalysts & solvents 2

HCID 702EthanolSolventHCID 312751,4-DioxaneSolvent

Procedure

A mixture of ethyl 4-[4-(methylthio)phenyl]-2,4-dioxobutanoate (1 g) and 4-fluorophenylhydrazine hydrochloride (0.67 g) in ethanol (10 ml) and dioxane (10 ml) was refluxed for 5 hours. The solvent was evaporated, and the residue was dissolved in chloroform and washed with water. The organic layer was dried over magnesium sulfate and concentrated. The residue (1.6 g) was purified by column chromatography on silica gel (30 g) eluting with a mixture of toluene and ethyl acetate (20:1) to give ethyl 1-(4-fluorophenyl)-3-[4-(methylthio)phenyl]pyrazole-5-carboxylate (0.11 g).

Workup

  1. temperaturewas refluxed for 5 hours
  2. customThe solvent was evaporated
  3. dissolutionthe residue was dissolved in chloroform
  4. washwashed with water
  5. dry with materialThe organic layer was dried over magnesium sulfate
  6. concentrationconcentrated
  7. customThe residue (1.6 g) was purified by column chromatography on silica gel (30 g)
  8. washeluting with a mixture of toluene and ethyl acetate (20:1)

Sources & evidence

ORD record
ord-1c4cb079726b421aab1c3c73283af74b
Source dataset
uspto-grants-1992_07
Patent number
US05134142

Reaction notes

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