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.
Benzothiazines are well‐recognized compounds in medicinal chemistry, and many derivatives have been explored as target structures in drug development. Fused-benzothiazines are of much interest for various fields of science as these scaffolds demonstrate a wide spectrum of biological applications like anti-microbial, anti-malarial, anti-cancer, anti-viral, ant-oxidant, anti-inflammatory, etc.