Synthesis, characterization, antimicrobial and antioxidant activity of some disubstituted [1,3,4]-oxadiazoles carrying 4-(methylsulfonyl/sulfinyl)benzyl moieties

Disubstituted [1,3,4]-oxadaiazoles (6a-b), Mannich bases (7a-f) and S-alkylated derivatives (8a-f) have been synthesized from 4-(methylsulfonyl/sulfinyl)phenylaceticacid (3a-b) through a multi-step reaction sequence starting from (4-methylthio)phenylacetonitrile (1). The structures of new compounds were established on the basis of their elemental analysis, IR, ¹H NMR, ¹³C NMR and mass spectral data. All the synthesized compounds were screened for their antioxidant, antibacterial and antifungal activity. Some of the derivatives have promising antimicrobial activity.