N‐1 Substituted ethyl 4‐pyrazolecarboxylates: Synthesis and spectroscopic investigations

Abstract
The synthesis of various N‐1 substituted ethyl 4‐pyrazolecarboxylates via reaction of ethyl 2‐formyl‐3‐oxo‐propionate (= ethoxycarbonylmalondialdehyde) with appropriately substituted hydrazines is described. Moreover, detailed nmr‐spectroscopic investigations with the title compounds are presented.