Benzimidazole is a benzo derivative of imidazole. It is a kind of bicyclic aromatic organic compounds, which is formed by fusing a six-membered benzene ring and five-membered imidazole at positions 4 and 5 of imidazole ring. It is an important pharmacophore of many biologically active heterocyclic compounds with various pharmacological activities. Benzimidazoles and their derivatives have developed into dynamic heterocyclic systems due to their potency in a variety of biologically active compounds such as anticancer, bactericidal and antiviral drugs. Benzimidazoles are a class of therapeutic motifs with broad relevance in medicinal chemistry.
Benzodioxanes are a class of isomeric compounds with the molecular formula C8H8O2. The three isomers of benzodioxane are 1,2-benzodioxane, 1,3-benzodioxane and 1,4-benzodioxane. 1,4-Benzodioxane has long been a versatile template widely used to design molecules with diverse biological activities. Its use spans past decades in medicinal chemistry to today, involving many drug discovery strategies, not excluding the most advanced ones. 1,4-Benzodioxane derivatives have been described as agonists and antagonists of nicotinic, alpha-adrenergic and 5-HT receptor subtypes. 1,4-Benzodioxane derivatives have been also reported as antitumor and antibacterial agents.