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.
Fusion heterocyclic compounds have various biological activities, such as anticancer, antibacterial, antifungal and anti-inflammatory, and thus have been widely used in the field of medicinal chemistry. Pyrrolopyrimidines are a major class of fused heterocyclic compounds. Compared with single pyrrole and pyrimidine cores, pyrrolopyrimidines have more diverse and effective pharmacological characteristics as fusion scaffolds.