SYNTHESIS AND IN-VITRO ANTIOXIDANT EVALUATION OF SOME NOVEL 4-(4-SUBSTITUTED) BENZYLIDENAMINO-4,5-DIHYDRO-1H-1,2,4-TRIAZOL-5-ONES

3-Alkyl (aryl)-4-amino-4,5-dihydro-1H-1,2,4-triazol-5-ones (2a-g) were reacted with 4-ethylbenzaldehyde to afford the corresponding 3-alkyl (aryl)-4-(4-ethylbenzylidenamino)-4,5-dihydro-1H-1,2,4-triazol-5-ones (3a-g). The acetylation reactions of compounds 3 were also investigated and compounds 4a-c, 4e, 4f were obtained. The new twelve compounds were characterized using IR, H-1 NMR, C-13 NMR and UV spectral data. In addition, 3 and 4 type compounds were screened for their antioxidant activities. Moreover compounds 4 were titrated potentiometrically with tetrabutylammonium hydroxide in four nonaqueous solvents such as isopropyl alcohol, tert-butyl alcohol, acetone, N,N-dimethylformamide and the halfneutralization potential values and the corresponding pKa values were determined in all cases.