Novodvorskyi Y. Synthesis of condensed 1,2,4-triazine derivatives and their modification

As part of this study, a strategy for the synthesis of biologically active heterocyclic compounds, known in the literature as "diversity-oriented synthesis" ("DOS"), was chosen. The common structural fragment of the new compounds obtained in the dissertation work is 1,2,4-triazine. Reactions of nucleophilic substitution of the alkylmercapto group in the 3rd position of the 1,2,4-triazine cycle became the initial stage of the synthesis of new substrates. The reagents for this type of reaction were hydrazine and 3-methylmercapto-1,2,4-triazin-5-one. The variety of substrates was created due to the presence of various alkyl and aryl solvents in the 6th position of the starting 1,2,4-triazin-5-ones. The diversity of the product is also provided by the presence of the 4-N-amino group in the 1,2,4-triazine molecule (deamination products of the original compounds). In this way, a library of 3-hydrazinyl-1,2,4-triazin-5-ones was obtained, which were also used as starting materials in heterocyclization and condensation reactions with Schiff-based formation. Aliphatic and aromatic amines were also used as nucleophilic agents for the substitution reaction in the 1,2,4-triazine nucleus. The conditions of these transformations were optimized again. Several of the simplest representatives of the obtained compounds were tested for anticonvulsant activity. Among such compounds, the products of substitution of the 3-alkyl mercapto group with morpholine, pyrrolidine and piperidine can be distinguished. Some of the studied compounds have demonstrated anticonvulsant activity and sedative effects in animal studies. The logical continuation of this part of the research was the synthesis of the reaction products of the original 3-alkylthio-1,2,4-triazin-5-ones with some tryptamines and 2-phenylethylamines. A large number of products of nucleophilic substitution in 1,2,4-triazine molecules was obtained.