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

Participants

Reaction Steps

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).

Provenance & Evidence