Synthetic approaches to fused heteroaromatic compounds by the condensation reactions of functional pyrroles

Condensation reactions ol the “functionalized” pyrroles which were obtained by one pot synthesis of aziridines and acetylenic dipolarophiles were discussed. On treatments of 3,4-di- and 2,3,4-tribenzoylpyrroles with hydrazine hydrate and phosphorus pentasulfide, the several pyrrolo-pyridazine derivatives and fused thiophenes, respectively, were prepared. The structure proofs for the products of the reaction of the 2,3,4-tribenzoylpyrrole ( 9a ) with hydrazine hydrate were based on the ¹³C FT-nmr spectrum of the corresponding ¹³C-enriched compounds.