Study of Reactions of Bis(4‐hydroxy‐6 H ‐1,3‐oxazine‐6‐ones) With Oxygen‐ and Nitrogen‐Containing Nucleophilic Reagents

Bis(1,3‐oxazine) derivatives are of great interest to heterocyclic chemistry due to their potential wide range of biological activity. According to research data, compounds of this series demonstrate antimicrobial, antifungal, and antioxidant activity. The relevance of studying bis(4‐hydroxy‐6 H ‐1,3‐oxazine‐6‐ones) is also related to their high reactivity, which is due to the presence of electron‐deficient oxazine cycles in reactions with nucleophilic reagents, resulting in the formation of both heteroaromatic and acyclic systems with different properties and pharmacological effects. Therefore, the aim of our work was to study the reactions of bis(4‐hydroxy‐6 H ‐1,3‐oxazine‐6‐ones) with oxygen‐ and nitrogen‐containing nucleophiles. As a result of interaction with N‐nucleophiles (hydrazine hydrate and phenylhydrazine), bis(1,2,4‐triazole) derivatives were obtained. The syntheses were carried out in boiling methanol or glacial acetic acid (GAA). It was observed an increase in the yield of the target compound in the GAA medium from 64% to 70% relative to the yield of the product in methanol. Interaction with ethanol led to the opening of the oxazine cycles, followed by the formation of diethyl esters of N‐acylmalonamic acids. Hydrolysis of bis(1,3‐oxazine) derivatives resulted in the production of polycarbonyl compounds.