Study of the electrochemical redox characteristics of some triazolopyrimidines

Abstract

An electrochemical study related to the redox characteristics of Ethyl-3-acetyl-6-methyl-1,4-diphenyl-4,3a-dihydro-1,3,4-triazolino[3,4-a] pyrimidine-5-carboxylate ester and its derivatives (1a-f) and (2a-e) in nonaqueous solvents such as 1,2-dichloroethane (DCE), dichloromethane (DCM), acetonitrile (AN), dimethylsulphoxide(DMSO) and tetrahydrofurane (THF) using 0.1 mol dm-3 tetrabutylammonium perchlorate (TBAP) as a supporting electrolyte at platinum, glassy carbon and gold electrodes , has been performed using cyclic voltammetry (CV). Controlled potential electrolysis (CPE) is also carried out to elucidate the course of different electrochemical reactions through the separation and identification of the intermediates and final electrolysis products .The redox mechanism is suggested and proved. It was found that all the investigated compounds in all solvents are oxidized in a single irreversible one electron donating process following the well known pattern of the EC-mechanism to give a dimer. On the other hand, these compounds are reduced in a single irreversible one electron step to form the anion radical, which is basic enough to abstract proton from the media forming the radical which undergoes tautomerization and then dimerization processes to give also another bis-compound through N-N linkage formation. Key words: Cyclic voltammetry, oxidation, reduction, triazolopyrimidine, non-aqueous media, platinum electrode, glassy carbon electrode, gold electrode.