A critical review of benzimidazole: Sky-high objectives towards the lead molecule to predict the future in medicinal chemistry

Out of several heterocyclic templates, the use of a Benzimidazole (BZ) scaffold is immensely observed. This fused heterocycle comprises two ring nitrogen atoms placed at 1st and 3rd position, in which the 1st nitrogen is connected to hydrogen that gets released to exhibit the acidic property. The use of BZ for the purpose of making clinically useful compounds was started in the year of 1944. BZ derivatives have been consistently used as effective chemotherapeutic agents to treat a diverse range of disorders. Apart from their clinical usefulness, BZ-based compounds also confer high safety, bio-availability, and stability. Out of several clinical conditions, cancer, and helminthiasis are a few where this template has been maximally utilized. The present review emphasizes chronologically the developments of BZ-based compounds in the entire scope of medicinal chemistry as antibacterial, anticancer, antifungal, anti-inflammatory, anti-HIV (human immunodeficiency virus), anticonvulsant, antioxidant, antidiabetic, antitubercular, antileishmanial, antimalarial, anti-histaminic. This review also covers patents on BZ of clinical importance till 2020. The primary objective of this review is to develop a comprehensive SAR (structure–activity relationship), which in turn assists the medicinal chemist to come up with novel ideas, while being implemented could produce novel compounds with enormous potential.