Serap Basoglu Ozdemir

Synthesis and antimicrobial activity of new piperazine-based heterocyclic compounds

Abstract The hydrazide 5, that was obtained from 1-(4-fluorophenyl)piperazine (1), was converted to the corresponding carbothioamides 6a–c by the reaction with alkyl(aryl) isothiocyanates. The synthesis of conazole analogs 10a–f was performed via the intermediary of triazoles 7a–c. The condensation of triazoles 7a–c with several heterocyclic amines in the presence of formaldehyde afforded the corresponding N-aminoalkylated triazoles 11–14. The effect of different catalysts and solvents on conventional and microwave (MW)-prompted reactions was examined. The synthesized compounds were screened for their antimicrobial activities.

Microwave-assisted and conventional synthesis of novel antimicrobial 1,2,4-triazole derivatives containing nalidixic acid skeleton

Abstract Carbothioamides 4a,b, obtained from nalidixic acid, were converted to the corresponding 1,3-thiazolidine derivatives 5a,b by cyclocondensation with 2-bromo-1-(4-chlorophenyl)ethanone. Treatment of 4a,b with base afforded 1,2,4-triazoles 6a,b. The synthesis of 1,3-oxazolidine 7 was performed by the reaction of compound 4a with ethyl bromoacetate. Treatment of 4a with acid produced 1,3,4-thiadiazole 8. The reaction of compounds 6a and 6b with several heterocyclic amines in the presence of formaldehyde gave the corresponding Mannich bases 9–15 containing various pharmacophore groups. Conventional and microwave-assisted methods were used for the synthesis. The effect of an acid catalyst on Mannich reactions was investigated. The structures of the newly synthesized compounds were elucidated on the basis of 1H NMR, 13C NMR, FTIR, EIMS techniques, and elemental analysis. All compounds were screened for their antimicrobial activity.