Etidronic acid catalyzed simple, facile and generalized synthetic protocol for preparation of 2-substituted-1H-benzo[d]imidazole-6-carboxylates

Abstract

Research in synthetic organic chemistry has observed ever continuing search for newer methodologies towards fused heterocycles; and benzimidazole core occupies central position in this search with many others, owing to its magnificent pharmaceutical properties.[1,2] The presence of the benzimidazole system in a natural productismost striking in the case of vitamin B12 (cyanocobalamin).[3] Benzimidazole derivatives are potent inhibitors of TIE-2 and VEGFR-2 tyrosine kinase receptors[4], antitumor agents[5], gammaaminobutyric acid (GABA) agonists[6], and 5-HT3 antagonists[7]. The scaffold is also known to inhibit the growth of grampositive bacteria and is active against various transplantable tumors.[8] Moreover, these fused heterocycles have been studied as new nonnucleoside topoisomerase-I poisons, human immunodeficiency virus-1 reverse transcriptase inhibitors, potent DNA gyrase inhibitors and potent anti-breast cancer agents.[9] They can act as ligands to transition metals for modeling