Review on the potential of 1,3,4-Oxadiazine derivatives: Synthesis, structure-activity relationship, and future prospects in drug development

1,3,4-Oxadiazine is a six-membered heterocyclic ring containing two nitrogen atoms and one oxygen atom. It is an important structural motif that has gained significant interest in the fields of pharmaceuticals, agrochemicals, and materials science due to its unique properties and versatile applications. The synthesis of 1,3,4-oxadiazine derivatives can be achieved through various methods such as cyclization of α,β-unsaturated nitriles, the reaction of hydrazides with carbonyl compounds, and condensation of nitriles with amidoximes. These synthetic routes offer a wide range of structural diversity and functionalization, making 1,3,4-oxadiazine derivatives attractive candidates for drug discovery and development. 1,3,4-Oxadiazine derivatives have been shown to possess a broad range of biological activities, including antitumor, antimicrobial, antiviral, and anti-inflammatory properties. During the literature search, it was observed that no review focuses on the SAR-based discussion of 1,3,4-oxadiazine ring-containing molecules used to treat various diseases. In order to address this issue in this review, we have discussed the synthetic route, US-granted patents, and structure-activity relationship (SAR) of the biologically active compound containing a 1,3,4-oxadiazine ring, as well as their current limitations and future prospects.