Oxadiazoles are a class of heterocyclic aromatic compounds with the molecular formula C2H2N2O, which have special biological activities and thermodynamic properties. Five-membered heterocyclic moieties composed of three or two heteroatoms are of great interest to researchers because these compounds show significant therapeutic potential. These heterocycles can serve as a building block for the development of novel molecular structures.
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.
The two N atoms in Benzothiadiazole could possibly form intermolecular hydrogen bonding, leading to a more planar backbone. Benzothiadiazole is a strong electron-accepting molecular fragment. By fusing it with thiazole donor-acceptor dyes, near-infrared fluorescence was created. The benzothiadiazole ring is a useful n-type building block for designing electron-transport materials for organic and polymer light-emitting diodes (LEDs). Arene- and heteroarene-fused thiadiazoles have also found use in the design of low-band-gap materials for the construction of organic field-effect transmitters (OFETs), as stable organic radicals, and as one or two photon-absorbing materials for the design of nonlinear near-infrared (NIR) dyes. Benzothiadiazoles acting as the electron-accepting cores have been incorporated into dendrimer-type light-harvesting materials.