Synthesis, spectral analysis and in vitro microbiological evaluation of 3-(3-alkyl-2,6-diarylpiperin-4-ylidene)-2-thioxoimidazolidin-4-ones as a new class of antibacterial and antifungal agents

In the present work, a new series of bis hybrid heterocycle comprising both piperidine and thiohydantoin nuclei together namely 3-(3-alkyl-2,6-diarylpiperin-4-ylidene)-2-thioxoimidazolidin-4-ones 46–60 was synthesized by the treatment of the respective thiosemicarbazones 31–45 with chloroethyl acetate and anhydrous sodium acetate in refluxing ethanol for 4 h and were characterized by melting point, elemental analysis, MS, FT-IR, one-dimensional NMR (1H, D2O exchanged 1H and 13C), two dimensional HOMOCOSY and NOESY spectroscopic data. In addition, the title compounds were screened for their antimicrobial activities against a spectrum of clinically isolated microbial organisms. Compounds 47–50, 52–55 and 57–60 with fluoro, chloro, methoxy or methyl functions at the para position of phenyl rings attached to C-2 and C-6 carbons of piperidine moiety along with and without methyl substituent at position C-3 of the piperidine ring exerted potent biological activities against Staphylococcus aureus, β-Hemolytic streptococcus, Vibrio cholerae, Escherichia coli, Pseudomonas aeruginosa, Aspergillus flavus, Candida albicans, Candida 6 and Candida 51 at a minimum inhibitory concentration.

In the present work, a new series of bis hybrid heterocycles comprising both piperidine and thiohydantoin nuclei compactly together as 3-(3-alkyl-2,6-diarylpiperin-4-ylidene)-2-thioxoimidazolidin-4-ones 46–60 were synthesized and their in vitro microbiological evaluation was carried out against clinically isolated bacterial and fungal strains.Figure optionsDownload as PowerPoint slide