A procedure for the preparation of the title salts via regioselective halocyclization of 3- S -propargylthio-4 Н -1,2,4-triazoles is reported. Stereoselectivity of electrophilic heterocyclization depends on the nature of the electrophilic reagent: bromination is better than iodobromination and iodination. The heterocyclization with tellurium tetrahalogenides leads to the formation of a mixture of geometric isomers of the salts. Their structure was confirmed by ¹ H NMR, ¹³ C NMR, НМВС and single crystal X-ray diffraction analysis.

Understanding the interactions between drugs and enzymes is crucial for designing effective therapeutics. This study employed a combination of molecular docking and molecular dynamics (MD) simulations to evaluate the binding affinity, stability, and dynamic behavior of two new compounds (compound 1 and compound 2) compared to vancomycin and meropenem against Staphylococcus aureus and Serratia marcescens bacterial enzymes. Molecular docking studies provided insights into the binding interactions and affinities of these compounds, revealing that both compound 1 and compound 2 exhibit promising binding profiles. In particular, compound 1 demonstrated lower binding energies with key enzymes from Staphylococcus aureus compared to vancomycin, suggesting enhanced potential. MD simulations further elucidated the dynamic stability of these complexes. Results indicated that compound 1 maintains consistent binding modes with low RMSD and RMSF values, implying stable interactions. In contrast, vancomycin exhibited high RMSD and RMSF values in some enzyme complexes, reflecting potential instability. Compound 2 showed competitive stability and binding behavior compared to meropenem, with comparable RMSD and RMSF values across various enzyme targets. These findings highlight the potential of compound 1 and compound 2 as viable candidates for further development, offering insights into their stability and efficacy as new therapeutic agents.

The reactions of [1,3]thiazolo[3,2- b ][1,2,4]triazol-7-ium salts with nucleophiles were investigated. Theoretical investigation of reactivity descriptors and structural parameters of [1,3]thiazolo[3,2- b ][1,2,4]triazol-7-ium cation was carried out, and the reactivity centers of the model salts were located. An efficient general method for the synthesis of novel poly-functional derivatives of symmetric triazoles from [1,3]thiazolo[3,2- b ][1,2,4]triazol-7-ium halides was developed. The structures of the synthesized compounds were confirmed using proton nuclear magnetic resonance ( ¹ H NMR), carbon-13 nuclear magnetic resonance ( ¹³ C NMR), Fourier-transform infrared spectroscopy (FTIR) and single-crystal X-ray analysis.

A convenient procedure for the regioselective preparation of [1,3]thiazolo[3,2- b ][1,2,4]triazol-7-ium 10 and [1,2,4]triazolo[5,1- b ][1,3]thiazin-4-ium salts 9 via regioselective electrophilic cyclization of 3-[(2-alken-1-yl)sulfanyl]-4 H -1,2,4-triazoles 3 is reported. Direction of electrophilic heterocyclization strongly depends on nature of the alkenyl substitutent.