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.
Tetrahydroquinoline is one of the most important simple nitrogen heterocycles, widely found in nature and in a variety of pharmacologically active compounds. Tetrahydroquinoline is an important structure for the synthesis of various biologically active derivatives.