Synthesis, characterization and investigation of antimicrobial and antioxidant activities of some new 2-[(4,5-dihydro-1H-1,2,4-triazol-5-one-4-yl)azomethine]phenyl 4-nitrobenzoate derivatives

The synthesis of 2-{[3-alkyl(aryl)-4,5-dihydro-1H-1,2,4-triazol-5-one-4-yl]azomethine}-phenyl 4-nitrobenzoates 3from the reactions of 3-alkyl(aryl)-4-amino-4,5-dihydro-1H-1,2,4-triazol-5-ones 1 with 2-(4-nitrobenzoxy)-benzaldehyde 2is described. The acetylation reactions of the compounds 3 giving compounds 4 have been investigated. The compounds 3 have also been treated with 4-piperidinecarboxamide / piperazine in the presence of formaldehyde according to the Mannich reaction to synthesize 2-{[1(4-piperidinecarboxamide-1-yl-methyl)-3-alkyl(aryl)-4,5-dihydro-1H-1,2,4-triazol-5-one-4-yl]azomethine}-phenyl 4-benzoates 5 and N,N '-bis-{3-alkyl(aryl)-4-[2-(4-nitrobenzoxy)-benzylidenamino]-4,5-dihydro-1H-1,2,4-triazol-5-on-1-yl-methyl}-piperazines 6. The newly synthesized compounds have been characterized using IR, H-1 and C-13 NMR, UV-Vis and mass spectral data. In addition, the newly synthesized compounds have been screened for their antimicrobial activities. Furthermore, these thirty one new compounds have been analyzed for their in vitro potential antioxidant activities by three different methods.