Synthesis, antifungal and antibacterial activity of calix[4]arene‐based 1,3,4‐oxadiazole derivatives

Abstract

AbstractWe describe the synthesis of some novel p‐tert‐butylcalix[4]arene‐based (5‐aryl‐1,3,4‐oxadiazol‐2‐yl)2‐chloroethanethioate derivatives (4a–e). These compounds were synthesized by the reaction of tetra‐tert‐butyl calix[4]arene (1) with (5‐aryl‐1,3,4‐oxadiazol‐2‐yl)2‐chloroethanethioate (3a–e) in the presence of potassium carbonate as a weak base and dry acetone as the solvent. All the newly synthesized calix[4]arene derivatives were characterized by elemental analysis and various spectroscopic methods such as FT‐IR, 1H NMR,13C NMR, DEPT, and ESI‐MS. The synthesized compounds were tested in vitro for their antibacterial and antifungal activities against Escherichia coli and Aspergillus fumigates in comparison with enrofloxacin and amphotericin as reference drugs, which are normally used for treating such infections. The synthesized compounds showed different inhibition zones against the tested bacteria and fungi. Compound 4c was found to be most effective against A. fumigates, whereas compound 4e was found to be equally effective against E. coli and A. fumigates.