Reactions with heterocyclic amidines VIII. Synthesis of some new imidazo[1,2‐b]pyrazole derivatives

The reaction of benzoylacetonitrile (III), its phenylazo derivative (X), malononitrile and malononitrile derivatives with ethyl hydrazinoacetate was investigated. All the investigated compounds with the exception of phenylazobenzoylacetonitrile and phenylazomalononitrile afforded 1‐ethoxycarbonylmethyl‐3‐aminopyrazole derivatives when treated with I. Compounds Xa and XVIII afforded imidazoypyrazole derivatives under the same experimental conditions.