2-Propenoic acid, 2-cyano-3-ethoxy-, ethyl ester → 3-(5-amino-4-(ethoxycarbonyl)-1H-pyrazol-1-yl)benzoic acid

Participants

Reaction Steps

The mixture of 3-hydrazinobenzoic acid (5.0 g) and ethyl 2-ethoxymethylene-2-cyanoacetate (5.6 g) in ethanol (50 ml) was heated under reflux for 2 hours under stirring, and then the mixture was evaporated in vacuo. To the residue was added a mixture of ethyl acetate and water, and the mixture was adjusted to pH 8 with 20% aqueous potassium carbonate solution. The separated aqueous layer was adjusted to pH 4 with 6N-hydrochloric acid and extracted with ethyl acetate. The extract layer was washed with water, dried over magnesium sulfate and evaporated in vacuo. The residue was triturated with a solution of ethyl acetate and diisopropyl ether and the precipitate was collected by filtration to give 3-(5-amino-4-ethoxycarbonylpyrazol-1-yl)benzoic acid (6.0 g).

Provenance & Evidence