Reaction of Diphenylcyclopropenethione with Heteroaromatic Nitrogen Compounds

Abstract

Diphenylcyclopropenethione reacts with a variety of heteroaromatic nitrogen compounds to give in excellent yields four types of products (a) 6,7-diphenyl-8-thionpyrazolo[1,2-a]pyridazine and -cinnolines, (b) azaindolizinthiols, (c) azaindolizine disulfides, and (d) 1-methoxy-1,2-diphenyl-3-thionpyrrolidino-[1,2-a]isoquinoline and similar structures. Proof of structure of products of type a rests on their independent synthesis by the action of phosphorus pentasulfide on the known oxo-analogs. Products of type b are converted readily into type c by air oxidation. In products of type d a molecule of solvent methanol is incorporated in the structures.