Synthesis, Antibacterial and Antifungal Activity of Some New 1,3,4-Oxadiazoles and 2-Substituted Amino-L,3,4-Oxadiazole Derivatives Containing Benzimidazole Moiety

New 2-[4-(3-acetyl-2-substituted- 2,3-dihydro-1,3,4-oxadiazol-5-yl)phenoxymethyl]-1H-bezimidazoles (V) and 2-[4-(3-acetyl-2-substituted-2,3-diydro-1,3,4-oxadiazol-5yl)phenoxymetyl]-1-methyl-1H-benzimidazoles (VI) were synthesized by cyclization of 2-[4-alkylidene or arylidenehydrazinocarbonyl)phenoxymethyl]-1H-benzimidazoles (III) or 2-[4-(alkylidene or arylidenehydrazinocarbonyl)phenoxymethyl]-1-methyl-1H-benzimidazoles (IV) with acetic anhydride. New series of 2-[4-substitutedamino-1,3,4-oxadiazol-5-yl)phenoxymethyl]-1H-benzimidazoles (IX) and 2-[4-substitutedamino-1,3 ,4-oxadiazol-5-yl)phenoxymethyl]-1-methyl-1H-benzimidazoles (X) were obtained by cyclodesulfurization of 2-[4-(substitutedthiocarbamoylhydrazinocarbonyl)phenoxymethyl]-1H-benzimidazoles (VII) or 2-[4-(substitutedthiocarbamoylhydrazi nocarbonyl)phenoxymethyl]-1-methyl-1H-benzimidazoles (VIII). The structure of the newly synthesized compounds were elucidated by elemental analysis, IR and 1H-NMR spectra. Their antimicrobial activity was studied.