Reaction of Cyclopropenones with Heteroaromatic Nitrogen Compounds

Abstract

Diphenylcyclopropenone reacts with a variety of heteroaromatic nitrogen compounds to give in good yield either (a) 1,2-diphenyl-3-indolizinyl cis-1,2-diphenyl acrylates and aza analogs, (b) 5,6-diphenyl-7-hydroxypyrrolo[1,2-b]pyridazines and similar structures, or (c) adducts in which cycloaddition takes place to an N=N bond. Proof of structure of the new heterocycles is based on deuterium labelling experiments, hydrogenolysis to known compounds, and the preparation of chloro and iminoether derivatives. Cycloheptenocyclopropenones in the examples studied form heterocycles of type b.