Heterocyclic compounds have strong interest in pharmaceutical research area because of their useful pharmacological activities. Heterocyclic compounds are abundant in nature and have acquired more importance because their structural subunits are exhibit in various natural products such as vitamins, hormones, antibiotics etc. The multifaceted chemical potential of 1,3-thiazine- a six membered species containing nitrogen and sulphur in the ring has led to unabated research in their synthetic methodologies. Thiazines are six membered heterocyclic compounds which have promising pharmacological activities which have drawn the attention of scientists and researchers. It is present in the fused form with β-lactam ring in major class of antibiotics like cephalosporins which shows the prevalence of thiazines. Thiazine compounds possess variety of pharmacological activities like anti-microbial, anti-mycobacterial, antifungal, antiviral, antitumor, antipsychotic, anti-inflammatory etc. The significance of thiazine derivatives has potential pharmacological moiety and future of these derivatives in the field of drug research. Some of the pharmacological activities are briefly summarized. This article summarizes various chemical reactions like condensation, cyclo-addition, ring transformations etc. The review focuses on thethiazine derivatives with potential activities that are now in development.