Ethanol → 5-methyl-1-(4-methylphenyl)-1H-pyrazole-4-carboxylic acid

HRID 1748427Notes

Reaction equation

HRID 1748427 reaction equation
C(O)C.C(O[CH:7]=[C:8]([C:14]([CH3:16])=O)[C:9]([O:11]CC)=[O:10])C.Cl.[CH3:18][C:19]1[CH:24]=[CH:23][C:22]([NH:25][NH2:26])=[CH:21][CH:20]=1.[OH-].[Na+]>O>[CH3:16][C:14]1[N:25]([C:22]2[CH:23]=[CH:24][C:19]([CH3:18])=[CH:20][CH:21]=2)[N:26]=[CH:7][C:8]=1[C:9]([OH:11])=[O:10]

Participants

6

Reactant 4

HCID 702EthanolHCID 125044-Methylphenylhydrazine monohydrochlorideHCID 14798Sodium HydroxideHCID 97734Butanoic acid, 2-(ethoxymethylene)-3-oxo-, ethyl ester

Product 1

HCID 27695835-methyl-1-(4-methylphenyl)-1H-pyrazole-4-carboxylic acidYield 57.7%

Reagents, catalysts & solvents 1

HCID 962WaterSolvent

Procedure

To an ethanol (70 ml) and water (70 ml) solution of ethyl 2-(ethoxymethylene)acetoacetate (16.67 g) prepared according to a method described in J. Chem. Soc. Perkin trans. I, 1875 (1988), was added 4-methylphenylhydrazine hydrochloride (14.2 g) and the mixture was stirred at reflux temperature for 7.5 hours. Sodium hydroxide (8.5 g) was added and the mixture was further stirred at reflux temperature for an hour. After completion of the reaction, the solvent was evaporated, diluted hydrochloric acid was added to the residue, and the mixture was extracted with ethyl acetate. The organic layer was dried over anhydrous magnesium sulfate and the solvent was evaporated. The residue was washed with n-hexane to give the titled compound (11.17 g).

Workup

  1. temperatureat reflux temperature for 7.5 hours
  2. stirringthe mixture was further stirred
  3. temperatureat reflux temperature for an hour
  4. customAfter completion of the reaction
  5. customthe solvent was evaporated
  6. additiondiluted hydrochloric acid was added to the residue
  7. extractionthe mixture was extracted with ethyl acetate
  8. dry with materialThe organic layer was dried over anhydrous magnesium sulfate
  9. customthe solvent was evaporated
  10. washThe residue was washed with n-hexane

Sources & evidence

ORD record
ord-c3f3e42018a94d56a631b599971ca2e4
Source dataset
uspto-grants-2015_10
Patent number
US09150555B2

Reaction notes

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