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Background: The aim of this study was to synthesize new mannich bases and conazol derivatives with biological activity by the microwave-assisted method. Introduction: 1,2,4-Triazole-3-one (3) acquired from tryptamine was transformed to the corresponding carbox(thio)amides (6a-c) via several steps. Compounds 6a-c were refluxed with sodium hydroxide to yield 1,2,4-triazole derivatives (7a-c). Compounds 3 and 7a-c on treatment with different heterocyclic secondary amines in an ambiance with formaldehyde afforded the mannich bases 8-15 having diverse pharmacophore units with biologically active sites. The reaction of compound 3 and 2-bromo-1-(4-chlorophenyl) ethanone in the presence of sodium ethoxide gave the corresponding product 2-substituted-1,2,4-triazole-3-one, 16, which was reduced to 1,2,4-triazoles (17). Synthesis of compounds 18, 19, and 20 was carried out starting from compounds 17 with 4-chlorobenzyl chloride (for 18), 2,4-dichlorobenzyl chloride (for 19), and 2,6-dichlorobenzyl chloride (for 20). Methods: The conventional technique was utilized for the synthesis of compounds, 3-7, and microwave- assisted technique for the compounds, 8-20. That is, green chemistry techniques were applied during these reactions. The structures of molecules were elucidated on the foundation of 1H NMR, 13C NMR, FT-IR, EI-MS methods, and elemental analysis. Novel synthesized molecules were investigated for their antimicrobial activity using MIC (minimum inhibitory concentration) method. Results: Aminoalkylation of triazole derivatives 3 and 7a-c with fluoroquinolones such as ciprofloxacin and norfloxacin provided an enhancement to the bioactivity of mannich bases 8-11 against the tested microorganisms. The MIC values ranged between <0.24 and 3.9 μg/mL. Moreover, molecules 10 and 11 exhibited more effects on M. smegmatis than the other compounds by the MIC values of <1 μg/mL. They have shown very good antituberculosis activity. Conclusion: Most of the synthesized structures were observed to have excellent antimicrobial activity against most microorganisms taken into account. These molecules have better activity than the standard drug ampicillin and streptomycin.

1,2,4-Triazole-3-one (3) obtained from tryptamine was transformed to the corresponding carbox( thio)amides via several steps (6a-d). Their reaction with sodium hydroxide performed the 1,2,4- triazole derivatives (7a-d). Compounds 7a-d treatment by 2-bromo-1-(4-chlorophenyl)ethanoneain an 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). Besides 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 a single hybrid compound. For this reason, a single compound containing more than one group, each with various modes of effect, could be helpful for the cure of bacterial infections. 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. The aminoalkylation of triazoles (7a-d) formed products 8a-d which have excellent activity against testing bacteria with values between 0.24 and 125 μg/mL. Especially compounds 8a and 8d exhibited much better activity against E. coli than ampicillin used as standard drug. The microwave process ensured a more efficient road to the creation of desired molecules. The antibacterial examination 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.

The amine (2) was prepared starting from 1-(4-fluorophenyl) piperazine via two steps, and then converted to the corresponding hydrazide (4). The reaction of hydrazide (4) with carbon disulfide generated the corresponding 1,3,4-oxadiazole (5), while the treatment of hydrazide with ethyl bromoacetate produced 4-oxo-2-thioxo-1,3-thiazolidine compound (6). The fourcomponent condensation of 4 with several aldehydes gave the corresponding 4-oxo-2-thioxo-1,3-thiazolidinglycinamides (7a-f). The synthesis of 4-oxo-1,3-oxazolidines (9a,b), 1,3-oxazoles (10a,b) and 1,3,4-triazoles (11a,b) was carried out starting from compounds 8a,b. Mannich bases (12a-d and 13a-f) were prepared using three component condensation of compounds 5 and 12a,b and corresponding amines. The synthesis of 16a-c, which were considered as the new analogues of azole class antifungals, was performed starting from the compound 14a via three steps. Results and Conclusion: All the reactions were examined under traditional and microwave irradiation conditions, and optimum conditions were defined. The antimicrobial activities of the newly synthesized compounds were screened and some of the tested compounds were displayed good-moderate antibacterial activity.

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