Synthesis and antioxidant properties of some 3-Alkyl(Aryl)-4-[3-ethoxy-2-(4- toluenesulfonyloxy)-benzylidenamino]-4,5-dihydro-1H-1,2,4-triazol-5-ones

A series of novel 3-alkyl(aryl)-4-[3-ethoxy-2-(4-toluenesulfonyloxy)-benzyliden-amino]-4,5-dihydro-1H-1,2,4- triazol-5-ones (4a-i) were synthesized from the reactions of 3-alkyl(aryl)-4-amino-4,5-dihydro-1H-1,2,4-triazol-5- ones (2a-i) with 3-ethoxy-2-(4-toluenesulfonyloxy)-benzaldehyde (3). The new compounds were characterized using by IR, 1H-NMR and 13C-NMR spectral data. In addition, the synthesized compounds were analyzed for their in vitro potential antioxidant activities in three different methods, including reducing power, free radical scavenging and metal chelating activity. These antioxidant activities were compared to those from standard antioxidants, such as EDTA, BHA, BHT and a-tocopherol.