Thiadiazoles are a subfamily of azoles. Structurally, they are five-membered heterocyclic compounds containing two nitrogen atoms and one sulfur atom, and two double bonds, forming an aromatic ring. Depending on the relative positions of the heteroatoms, there are four possible structures; these forms do not interconvert and are therefore structural isomers rather than tautomers. These compounds themselves are rarely synthesized and have no particular utility, however, compounds that use them as structural motifs are fairly common in pharmacology.
Benzotriazole is a bicyclic nitrogen heterocycle formed by the fusion of the benzene ring with the 4,5-positions or the “d” site of 1H-1,2,3-triazole. The benzotriazoles are known as important intermediates in the preparation of organic products such as β-amido ketones, aldehydes, β-ketoesters, ionic liquid, and as reagents for acylation and thioacylation reactions. 1H-Benzotriazoles are also known to exhibit broad spectrum of pharmacological activities. There are numerous benzotriazole-based clinically used drugs in the market for the treatment of various diseases.