Synthesis and alkylation of 5-aryl-1,2-dihydro-3H-1,2,4-triazole-3-thiones

Abstract

5-R-1,2,4-triazole-3-thiones and their derivatives are easy to obtain; they have low toxicity and a broad spectrum of the biological activity. It makes this class of heterocyclic compounds promising for creating potential drugs. Aim. To develop the preparative methods for the synthesis of 5-aryl-1,2-dihydro-3H-1,2,4-triazole-3-thiones and study their reactivity in the alkylation reaction. Results and discussion. New 5-aryl-1,2-dihydro-3H-1,2,4-triazole-3-thiones were synthesized. The latter were used for the synthesis of 3-aryl-5-(alkylthio)-4H-1,2,4-triazoles. Experimental part. Using a series of four successive reactions based on the substituted benzoic acids new 5-aryl-1,2-dihydro-3H-1,2,4-triazole-3-thiones were synthesized. Alkylation of the thiones allowed obtaining a series of S-alkyl derivatives. The structure of the compounds synthesized was confirmed by elemental analysis, IR and 1H NMR spectroscopy, and their individuality was determined by high-performance liquid chromatography. Conclusions. The preparative methods have been developed, and new 5-aryl-1,2-dihydro-3H-1,2,4-triazole-3-thiones have been synthesized. Alkylation of the latter made it possible to obtain a series of 3-aryl-5-(alkylthio)-4H-1,2,4-triazoles with an alkylthio fragment of different length.