Synthesis and free radical scavenging activity of some 1,3,4-thiadiazole derivatives

5-[(4-Acetamido) benzenesulphonamido]-1,3,4-thiadiazol-2-(N-benzoyl)sulphonamides (8a-g) were synthesized from 5-amino-1,3,4-thiadiazol-2-[N-(benzoyl) sulphonamides (4a-d) and 4-acetamidobenzenesulphonyl chlorides (7a). 5-[4-amino)]-benzenesulphonamido]-1,3,4-thiadiazol-2-[N-benzoyl] sulphonamides (9a-g) were obtained by hydrolysis of (8a-g) using 20% aq sodium hydroxide solution while, 5-(4-amino) benzenesulphonamido-1,3,4-thiadiazol-2-sulphonamides (10a-b) were obtained by hydrolysis of (9a-g) using 70% sulphuric acid respectively. Compounds were characterized by their analytical and spectral data. They were further screened for their in vitro free radical scavenging activity.