Benzothiophene is an aromatic organic compound with the molecular formula C8H6S and a naphthalene-like odor. Benzothiophenes are used in research as a starting material for the synthesis of larger, often biologically active structures. It exists in medicinal chemical structures such as raloxifene, zileuton, and sertaconazole, and can also be found in BTCP. It is also used to make dyes such as thioindigo.
Tetrazoles are doubly unsaturated five-membered aromatic heterocycles consisting of one carbon atom and four nitrogen atoms. Tetrazole derivatives are a major class of heterocyclic compounds that are important for medicinal chemistry and drug design because of their not only isosteric properties with carboxylic acid and amide moieties, but also metabolic stability and other beneficial physicochemical properties.