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.
Oxazolidines are five-membered ring compounds consisting of three carbons, nitrogen and oxygen. Oxygen and nitrogen are in the 1 and 3 positions, respectively. Oxazolidine is in general yellow or slightly yellow, alkaline liquid or solid, easily hydrolyzed by water or alcohol. It is insoluble in water (or hydrolyzed); soluble in benzene and chloroform. Oxazolidine derivatives are five-membered cyclic compounds containing at least one oxygen and nitrogen in their molecular structure. Oxazolidine derivatives are known to possess various therapeutic activities, such as anticancer and antibiotic properties.