Antibacterial and antioxidant activities of novel 2-ethoxy- 4-[(4,5-dihydro-1H-1,2,4-triazol-5-one-4-yl)azomethine]- phenyl 3-methoxybenzoate derivatives

In the present study, 3-alkyl/aryl-4-amino-4,5-dihydro-1H-1,2,4-triazol-5-ones (1) reacted with 3-ethoxy-4- (3-methoxybenzoxy)-benzaldehyde (2) to obtain the corresponding nine new 2-ethoxy-4-[(3-alkyl/aryl-4,5-dihydro-1H- 1,2,4-triazol-5-one-4-yl)azomethine]-phenyl 3-methoxybenzoates (3). The compounds 3 were also treated with 4- piperidinecarboxamide in the presence of formaldehyde according to the Mannich reaction to synthesize 2-ethoxy-4-{[3- alkyl/aryl-1-(4-piperidinecarboxamide-1-yl-methyl)-4,5-dihydro-1H-1,2,4-triazol-5-one-4-yl]-azomethine}-phenyl 3- methoxy-benzoates (4). The structures of Schiff base and Mannich base derivatives were identified with spectral methods. Antimicrobial and antioxidant screening were carried out and discussed. Mannich base derivatives were found to be more active than Schiff bases in the biological screening. The effect values of Mannich Base derivatives dominate Neomycin and Streptomycin antibiotics.