An efficient synthesis of novel heterocycle-fused derivatives of 1-oxo-1,2,3,4-tetrahydropyrazine using Ugi condensation

We present a convenient synthesis of novel pyrrole- and indole-fused 1-oxo-1,2,3,4-tetrahydropyrazine heterocyclic structures using a novel modification of four-component Ugi condensation. We demonstrate the usefulness and versatility of the developed approach for the synthesis of variously substituted compounds, and discuss the scope and limitations of the chemistry involved.