Progress on the Synthesis of Pyrido[1,2-a]benzimidazoles

Pyrido[1,2-a]benzimidazole is one of the important azaheterocycles with three fused aromatic rings. These molecules containing this skeleton have wide application prospects in the fields of medicinal chemistry and materials, and their syntheses have attracted much attention in organic chemistry. According to the retrosynthetic analysis on the construction of different rings in target molecules, the research progress on the synthesis of pyrido[1,2-a]benzimidazoles from different types of starting materials is reviewed, and its future development direction is prospected.