Studies on Some N-(4-Substitutedbenzylidene)-5-Phenyl-1,3,4-Thiadiazole-2-Amine Derivatives

In this study, 9 new compounds having 2-substituted-5-phenyl-1,3,4-thiadiazole structures were synthesized and their antifungal and antibacterial activities were evaluated. Target compounds were synthesized by reaction of 5-phenyl-1,3,4-thiadiazole-2-amine and substituted benzaldehydes with acetic acid. The structures of synthesized compounds were proved by IR, 1H-NMR, mass spectra and elemental analysis data.When the activity results were examined, it was seen that the compounds were not as effective as gentamicin and fluconazole which are standard compounds against S. aureus, P. aeruginosa, E. faecalis, E. coli, C. albicans, C. parapsilosis and C. krusei. When the antibacterial activities of the compounds were examined, it was seen that compounds 1, 3, 6 and 7 had higher activities compared to that of other compounds, however it was observed that the presence of the substituents at 2 position didn't create a significant difference on the activity. When the antifungal activities of the compounds were examined, it was seen that the compounds 1, 4 and 6 were not affected by the change of the substituents at the position 2. It was determined that the length of the carbon chain at the para position of piperazine did not affect the activity (Compounds 5 and 9) but where as the addition of benzyl group to the para position increased the activity (Compound 6). Meanwhile, it was seen that the activity of Compound 7 which includes piperidine ring was lower then that of compounds with piperazine substituent.