Experimental and theoretical study on the regioselective synthesis and reaction of some bis- and poly(3-mercapto-1,2,4-triazin-5(4H)-one) derivatives

The synthetic utility of 3-thioxo-1,2,4-triazin-5-ones 1 and 4-amino-3-mercapto-1,2,4-triazin-5(4H)-ones 2 as building blocks for novel bis- and poly(1,2,4-triazines) via alkylation with the corresponding bis- and poly(halo) compounds was investigated. Prediction of the site of alkylation has been confirmed using spectroscopic data. Theoretical calculation using hybrid density functional method wb97xd and 6-311++g(d,p) as basis set was implemented to investigate the reaction products energetics parameters. The atomic charges were calculated and discussed in details using three different methods. The transition state search were implemented to estimate the Gibbs free activation energy barrier of the reaction to emphasis the experimental results. (C) 2019 Elsevier B.V. All rights reserved.