Synthesis, Spectral Characterization and Analytical Profiling of Novel Saccharin-1,3,4-Thiadiazole Hybrids with Evaluation of Their Biological Activities.

Abstract

Abstract

Novel of saccharin derived 1,3,4-thiadiazole derivatives were synthesized from the reaction of sodium saccharin with allyl chloride, then allyl saccharin was hydrolyzed with equimolar KOH, the product was achieved after neutralized with HCl to pH = 5 to form 2-(N-allyl sulfamoyl) benzoic acid, which in turn was reacted with thiosemicarbazide in the presence of phosphorous oxychloride (POCl3) to give 2-amino-5-(N-allyl-6-sulfamoyl phenyl)-1,3,4-thiadiazole. The previous compound finally was diazotized with some substituted phenols with NaNO2 and HCl to afford the target products (1a-7a). The (1a-7a) derivatives were characterized using the analytical and spectral methods like Uv-Vis, FTIR, 1H-NMR and 13C-NMR shown in this work. The compounds were tested for their biological activity, where derivatives (3a and 4a) exhibited the highest activity against the tested bacteria (Staphylococcus aureus and Escherichia coli). Higher activity was recorded for compounds (3a and 4a) against Escherichia coli, moderate activity was recorded against Staphylococcus aureus were recorded for the same compounds. Moderate activity for (1a and 2a) were estimated against both bacteria, while the remaining showed low activity. The derivatives were tested as antioxidants (reducing activity) against Fe (III) and Cu II) to reduce them to Fe (II) and Cu (I) respectively, the results showed that the highest antioxidant activity derivatives against Fe (III) and Cu (II) were (3a and 4a) where (3a: 0.0085, 4a: 0.0082) against Fe(III) and (3a: 0.76, 4a: 0.73) against Cu (II).