Synthesis of N‐ureido Pyrrole Derivatives Through Gold‐Catalysed Reaction: Solvent and Catalyst Effect

Substituted pyrroles were obtained as a result of metal‐catalyzed cyclization of α propargyl acetophenone and α‐propargyl‐β‐ketoesters with semicarbazide. Optimum conditions and general procedures with high yields were established in a single pot. Eleven different N ‐ureido‐pyrrole derivatives were successfully yielded. Different ynone derivatives having various functionalities did not affect the cyclization reaction but except a slight decrease in product yield. Screening of optimum catalyst revealed that gold(III) chloride was the best catalyst for the cyclization reaction. We believe that this is the first time an N ‐ureido‐pyrrole skeleton starting from ynone has been synthesized in the literature.