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.
Benzoxazines are a type of heterocyclic compounds consisting of benzene and oxazine rings. Benzoxazine research is developing rapidly because of the many potential applications of the materials.