A Feasible Synthesis of Benzimidazonaphthyridines Involving Suzuki and C–N Cross-Coupling Reactions

A facile synthesis of a biologically significant fused heterocyclic system comprising benzimidazole and 1,6-naphthyridine is described. The synthetic approach involves three reactions: Suzuki coupling, imidazole construction, and C–N cross-coupling. The Suzuki coupling of 2-chloro-3-formylquinolines with (2-bromo­phenyl)boronic acid, followed by condensation with 1,2-diaminoarenes and subsequent palladium-catalyzed C–N cross-coupling, afforded benzimidazonaphthyridines, a privileged heterocyclic scaffold. The strengths of the protocol include the ready availability of the precursors, simple procedures, and good yields.