In VirtoAntioxidant Activities of New 4,5-Dihydro-1H,2,4-triazol-5-ones having Thiophene Ring with their Acidic Properties

Abstract

Seven new 3-alkyl(aryl)-4-(2-thienymethylenamino)-4,5-dihydro-1H-1,2,4-triazol-5-ones(2)were synthesized by the reactions of 3-alkyl(aryl)-4-amino-4,5-dihydro-1H-1,2,4-triazol-5-ones(1)with thiophene-2-carbaldehyde. In addition,N-acetyl derivatives of compounds2d-2gwere also prepared. The structures of eleven new compounds synthesized were determined by elemental analysis as well as IR, NMR and UV spectral data. In addition, compounds2a-gand3a,3b,3d-fwere also screened for their antioxidant activities and2a-gwere potentiometrically titrated with tetrabutylammonium hydroxide (TBAH) in four nonaqueous solvents (isopropyl alcohol,t-butyl alcohol, acetonitrile andN,N-dimethyl formamide). Also half-neutralization potential values and the corresponding pKa values were determined in all cases.