Benzimidazole(s): synthons, bioactive lead structures, total synthesis, and the profiling of major bioactive categories.

Benzimidazole, a fused bicyclic compound with benzene and pentacyclic 1,3-diazole moeities, has a simple aromatic heterocyclic structure. The moiety has become an indispensable anchor for the development of new pharmacologically active products, and has yielded several therapeutic agents with anticancer, antihypertensive, antimicrobial, antifungal and antiulcer effects. Benzimidazoles, as synthetically feasible and pharmacophoric synthons, have been relentlessly pursued for the preparation of new analogues and derivatives, and they have successfully developed into some of the most sought-after and vital pharmacophores for drug discovery. The use of varied substituents and differing patterns around the benzimidazole nucleus has provided a wide spectrum of biological activities. In addition, the benzimidazole moiety constitutes a building block for the production of several drugs, drug candidates, new chemical entities, and lead molecules. The importance of this nucleus for bioactivity, , antibacterial, antitubercular, antidiabetic, anticancer, antifungal, anti-inflammatory, analgesic, antioxidant, antihistaminic, and antimalarial activity, has led us to take note and provide an overview of the synthetic development approaches for various benzimidazole derivatives together with their biological actions. This review is projected to further assist in the design and development of new benzimidazole-based compounds for new and optimized pharmacologically active products towards new drug-development strategies.