The new compounds AP-1 to AP-10 were synthesized from starting material (2S)-3-(benzyloxy)-2-[(tert-butoxycarbonyl) amino]propanoic acid (1). The intermediate 2,5-disubstituted-1,3,4-thiadiazole amine (5) was prepared by coupling of (2S)-3-(Benzyloxy)-2-[(tert-butoxycarbonyl) amino]propanoic acid (1) with pyridine-2-carboxylic acid hydrazide (2) in the presence of carbonyldiimidazole (CDI) followed by 1,3,4-thiadiazole ring formation via diacylhydrazines derivative (3) and deprotection with shorter reaction time and excellent yield. The structures of new compounds were confirmed by spectral analysis. The series of new synthesized compounds AP-1 to AP-10 were evaluated for their anti-microbial activities in vitro and compounds AP-1, AP-3, AP-4, and AP-10 showed strong activities against all tested microorganisms. [ABSTRACT FROM AUTHOR]