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.
Thiadiazoles are a subfamily of azoles. Structurally, they are five-membered heterocyclic compounds containing two nitrogen atoms and one sulfur atom, and two double bonds, forming an aromatic ring. Depending on the relative positions of the heteroatoms, there are four possible structures; these forms do not interconvert and are therefore structural isomers rather than tautomers. These compounds themselves are rarely synthesized and have no particular utility, however, compounds that use them as structural motifs are fairly common in pharmacology.
Search 
+86 21 5895 0110 
