Conventional and Microwave Assisted Synthesis of Novel 1,2,4-Triazole Derivatives Containing Tryptamine Skeleton and Evaluation of Antimicrobial Activity

Background: 1,2,4-Triazole-3-one (3) obtainedafromatryptamine was transformed toatheacorresponding carbox(thio)amides via several steps (6a-d). Their reaction withasodiumahydroxide performed the 1,2,4-triazole derivatives (7a-d). Compounds 7a-d treatment by 2-bromo-1-(4-chlorophenyl)ethanoneain a ambiance with sodium ethoxide afforded the compounds (8a-d). The reduction reaction of 8a-d afforded 1,2,4-triazoles (9a-d). The synthesis of (10a-d), (11a-d) and (12a-d) was afforded treatment of products 9a-d with 4-chlorobenzyl chloride (for 10a-d) or 2,6-dichlorobenzyl chloride (for 11a-d) or 2,4-dichlorobenzyl chloride (for 12a-d). Objective: Beside the improved of entirely novel agents having various chemical features than those of the existing ones, another aim is to combined two or more groups into single hybrid compound. For this reason a single compound containing more than one group, each with various mode of effect, could be helpful for the cure of bacterial infectious. Methods: Microwave-assisted and conventional techniques were utilized for the syntheses. The structures of recently obtained molecules were elucidated on the foundation of 1H NMR, 13C NMR, FT IR, EI MS methods and elemental analysis. All novel synthesized molecules were investigated for their antimicrobial activity using MIC (minimum inhibitory concentration) method. Results: The aminoalkylation of triazoles (7a–d) formed products 8a-d which have excellent activity against to test bacteria with values between 0.24 and 125 μg/mL. Especially compound 8a and 8d exhibited much better activity against to E. coli than ampicillin used as standard drug. Conclusion: Microwave process ensured more efficient road the creation of desired molecules. The antibacterial examining demonstrated that after the carbonyl group is increased the antibacterial activity of the compounds is greatly increased. That's why molecules formed as a result of the alkylation reactions of triazoles has high activity.