Synthetic routes to benzimidazole-based fused polyheterocycles.

The review article represents a survey covering the synthetic strategies leading to benzimidazolebased fused polyheterocyclic systems utilizing simple reactive benzimidazole synthons since 1980. The polyheterocyclic systems are classified based on the number of rings; tetra-, penta-, hexa- and hepta-fused ring systems. Among each polyheterocyclic system, further classification according to the number of heterotoms; two-, three-, four-, five-, six- and seven heteroatoms is considered. [ABSTRACT FROM AUTHOR]