Synthesis of 2-Oxopyrrole-fused 1,n-Diazaheterocyclic Compounds and Substituted 2-Oxopyrroles via a Three-Component Reaction

摘要

An effective route to 2-oxopyrrole-fused 1,n-diazaheterocyclic compounds and substituted 2-oxopyrroles is described. This involves reaction of 1,n-diamines or monoamines 1 and nitroketene dithioacetal (1,1-di (methylthio)-2-nitroethene) in the presence of dialkyl acetylenedicarboxylate 2 in EtOH to give 2-oxopyrrole derivatives 3 in good yields (Table 1). The structures were corroborated spectroscopically (IR, ~1H and ~(13)C NMR, and EIMS) and by elemental analyses. A plausible mechanism for this type of cyclization is proposed (Scheme 1).