Studies in the ethylenimine ketone seriess with phenylhydrazine have shown that the trans form of aryl aroyl ethylenimines successfully competes with the cis form for one equivalent of the reagent to give a 4-aminopyrazoline which on further heating loses a molecule of amine to produce a pyrazole. The cis form reacts more slowly and only the pyrazole can be isolated. Previous investigators3vg have shown that certain epoxyketones will react with ...
