Synthesis of 1-Acyl-5-amino-4-ethoxycarbonylpyrazoles from Monohydrazides of Cyclohexenedicarboxylic Acids and Ethyl Ethoxymethylenecyanoacetate

Heating monohydrazides of cyclohexenedicarboxylic acids with ethyl ethoxymethylenecyanoacetate at reflux gives the corresponding N-substituted hydrazides. This reaction carried out in pyridine gives 1-acyl-5-amino-4-ethoxycarbonylpyrazoles.