Thiophene is a five-membered heterocyclic compound containing a sulfur heteroatom with the molecular formula C4H4S. Thiophene is aromatic and is very similar to benzene; electrophilic substitution reaction is easier than benzene, and it is mainly substituted at the 2-position. Thiophene ring system has certain stability to oxidant.
Pyrrolidine, also known as tetrahydropyrrole, is a saturated five-membered heterocyclic ring, which is miscible with water. Pyrrolidine exists in many alkaloids and drug molecules, such as kappa opioids, antagonists of dopamine D4 receptors, and HIV reverse transcriptase inhibitors.
Benzothiazoles are aromatic heterocyclic compounds with the chemical formula C7H5NS. Benzothiazoles and their derivatives are a very important class of heterocyclic compounds that are ubiquitous in nature and are mainly used in medicine, agriculture and industry. In medicine, benzothiazole derivatives are a kind of very important pharmaceutical intermediates with good pharmacological and biological activities. It can be used as a fungicide, anti-tuberculosis drug, anti-malarial, anti-convulsant, insecticide, sedative and anti-inflammatory drug, and can also be used to treat diabetes and has anti-cancer effects.