The condensation reaction of 5-(4-aminophenyl)-N-aryl-1, 3, 4-thiadiazol-2-ylamines with salicyl-aldehyde, 3-hydroxybenzaldehyde, 4-hydroxybenzaldehyde, 5- bromosalicylaldehyde, 5-chlorosalicyl-aldehyde, 4-methoxybenzaldehyde, 3- nitrobenzaldehyde, and 4-nitrobenzaldehyde results in series of new Schiff bases. The synthesized compounds were tested for their antimicrobial efficiency against ...