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.
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.
Isoxazole is a liquid heterocyclic compound C3H3NO isomeric with oxazole and having a penetrating odor like that of pyridine. Isoxazoles belong to an important class of five-membered aromatic heterocycles containing two electronegative heteroatoms, nitrogen and oxygen, in a 1,2-relationship and three regular sp2 carbon atoms. These molecules are found to be key components in various synthetic products in daily use and also present as a pharmacophore essential for biological activity in many drugs and bioactive natural products. In addition, isoxazoles have demonstrated their ability to exhibit hydrogen bond donor/acceptor interactions with a variety of enzymes and receptors.