The efficient synthesis of novel azetidin-2-ones 6 has been established. Thus, condensation of 5-[(2-methyl-1H-benzimidazol-1-yl)methyl]-1,3,4-thiadiazol-2-amine 4 with various aromatic aldehydes afforded 5-[(2-methyl-1H-benzimidazol-1-yl)methyl]-N-[(substituted) phenylmethylidene]-1,3,4-thiadiazol-2-amine 5 which on cycloaddition with chloroacetyl chloride in the presence of triethylamine catalyst yielded 3-chloro-1-{5-[(2-methyl-1H-benzimidazol-1-yl)methyl]-1,3,4-thiadiazol-2-yl}-4-(substituted) phenylazetidin-2-one 6. Structures of the synthesized compounds have been elucidated on the basis of their elemental analyses and spectral data. All the synthesized compounds were screened for their antimicrobial activity.