Chemistry of pyrrolic compounds. II. Some aspects of the chemistry of dipyrryl ketones

The synthesis of 3,5,4',5?-tetramethyl-2,2'-dipyrrylketone is described and the tautomeric structure of the compound investigated. It is concluded on spectroscopic grounds that this ketone and other members of the class exist mainly as the keto tautomer. The synthesis of a new heterocyclic system, the dipyrrolopyrimidones, is described.