Phenylhydrazine → Ethyl 3-methyl-1-phenylpyrazole-5-carboxylate

HRID 1816620Notes

Reaction equation

HRID 1816620 reaction equation
O=[C:2]([CH2:8][C:9](=O)[CH3:10])[C:3]([O:5][CH2:6][CH3:7])=[O:4].[C:12]1([NH:18][NH2:19])[CH:17]=[CH:16][CH:15]=[CH:14][CH:13]=1>C(O)(=O)C>[CH3:10][C:9]1[CH:8]=[C:2]([C:3]([O:5][CH2:6][CH3:7])=[O:4])[N:18]([C:12]2[CH:17]=[CH:16][CH:15]=[CH:14][CH:13]=2)[N:19]=1.[CH3:10][C:9]1[N:18]([C:12]2[CH:17]=[CH:16][CH:15]=[CH:14][CH:13]=2)[N:19]=[C:2]([C:3]([O:5][CH2:6][CH3:7])=[O:4])[CH:8]=1

Participants

5

Reactant 2

HCID 7516PhenylhydrazineHCID 69208Ethyl 2,4-dioxovalerate

Product 2

HCID 2746772Ethyl 3-methyl-1-phenylpyrazole-5-carboxylateHCID 10900438Ethyl 5-methyl-1-phenyl-1H-pyrazole-3-carboxylate

Reagents, catalysts & solvents 1

HCID 176Acetic AcidSolvent

Conditions

Temperature
100 °C

Procedure

2 ml ethyl 2,4-dioxovalerate and 1.2 g phenyl hydrazine were dissolved in 20 ml acetic acid, followed by stirring at 100° C. for 2 hours. After evaporating acetic acid, ethyl acetate was added to the residue. The mixture was washed with aqueous sodium hydrogencarbonate solution and brine, dried over anhydrous magnesium sulfate and evaporated. The residue was subjected to silica gel column chromatography, to give 0.37 g of ethyl 3-methyl-1-phenyl-1H-5-pyrazolecarboxylate with hexane:ethyl acetate (14:1) and 0.46 g of ethyl 5-methyl-1-phenyl-1H-3-pyrazolecarboxylate with hexane:ethyl acetate (9:1).

Workup

  1. customAfter evaporating acetic acid, ethyl acetate
  2. additionwas added to the residue
  3. washThe mixture was washed with aqueous sodium hydrogencarbonate solution and brine
  4. dry with materialdried over anhydrous magnesium sulfate
  5. customevaporated

Sources & evidence

ORD record
ord-f288b1ed3a0a4d9b8821f343cbfd88bf
Source dataset
uspto-grants-2005_04
Patent number
US06884821B1

Reaction notes

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