A series of 1,2,4-triazole and 1,2,4- thiadiazole derivatives were prepared starting from ethyl 4-(3-methyl-5-oxo-1,5-dihydro-4H-1,2,4-triazol-4-yl)benzoate. Firstly, both ethyl ester groups were simultaneously transformed into hydrazide groups, then into thiosemicarbazide groups using both microwave-assisted and conventional methods. The latter products were interacted with NaOH and H2SO4 to form ring assemblies containing two 1,2,4-triazole and 1,3,4-thiadiazole fragments, respectively. Antioxidant activities of the synthesized compounds were determined with CUPRAC, ABTS, and DPPH assays. Most of the compounds showed significant antioxidant activity and especially, compound 3 exhibited very good SC50 value for DPPH method and compound 3, 4a, 5a exhibited very high scavenging activity to the ABTS method. In addition, the in silico analysis was carried out with the synthesized derivatives to understand the mode of interaction with superoxide dismutase (SOD) and human tyrosine kinase using docking protocols in order to find out the most active antioxidant drug having high inhibitory activity in cancer.