Phenylhydrazine → Ethyl 5-amino-1-phenyl-1H-pyrazole-4-carboxylate

HRID 1731253

Reaction equation

HRID 1731253 reaction equation
[C:1]1([NH:7][NH2:8])[CH:6]=[CH:5][CH:4]=[CH:3][CH:2]=1.C(O[CH:12]=[C:13]([C:19]#[N:20])[C:14]([O:16][CH2:17][CH3:18])=[O:15])C>C(O)C>[NH2:20][C:19]1[N:7]([C:1]2[CH:6]=[CH:5][CH:4]=[CH:3][CH:2]=2)[N:8]=[CH:12][C:13]=1[C:14]([O:16][CH2:17][CH3:18])=[O:15]

Participants

4

Reactant 2

HCID 7516PhenylhydrazineHCID 789432-Propenoic acid, 2-cyano-3-ethoxy-, ethyl ester

Product 1

HCID 85270Ethyl 5-amino-1-phenyl-1H-pyrazole-4-carboxylateYield 55.7%

Reagents, catalysts & solvents 1

HCID 702EthanolSolvent

Procedure

A solution of 31.9 g of phenylhydrazine and 50.0 g of ethyl (ethoxymethylene)cyanoacetate (both reactants were obtained from Aldrich Chemical Company, Milwaukee, Wis.) disssolved in 500 ml of ethanol was refluxed for 6 hours. The mixture was allowed to stand for approximately 48 hours and was refluxed for an additional 8 hours. The reaction mixture was poured into ice water and the precipitated solid was collected by filtration. The solid was recrystallized from ethanol to afford 38.0 g of 5-amino-1-phenyl-1H-pyrazole-4-carboxylic acid, ethyl ester. Yield 44%. mp=101°-103° C.

Workup

  1. temperaturewas refluxed for 6 hours
  2. temperaturewas refluxed for an additional 8 hours
  3. filtrationthe precipitated solid was collected by filtration
  4. customThe solid was recrystallized from ethanol

Sources & evidence

ORD record
ord-9b8cd8417ca44baea26eee0eb07b028d
Source dataset
uspto-grants-1986_11
Patent number
US04620865

Linked notes

Loading…