Synthesis and spectral characterization of a new class of N-(N-methylpiperazinoacetyl)-2,6-diarylpiperidin-4-ones: Antimicrobial, analgesic and antipyretic studies

A series of N-(N-methylpiperazinoacetyl)-2,6-diarylpiperidin-4-ones (13c–21c) were synthesized by the base catalyzed nucleophilic substitution of N-chloroacetyl-2,6-diarylpiperidin-4-ones obtained from their corresponding 2,6-diarylpiperidin-4-ones with N-methylpiperazine. These newly synthesized compounds were characterized by one- and two-dimensional NMR spectral studies. In all the cases, the piperazine ring adopted normal chair conformation with equatorial orientation of methyl group irrespective of the non-chair conformations of the piperidin-4-one moiety. All the compounds were screened for their possible antibacterial and antifungal activities against a spectrum of microbial agents besides analgesic and antipyretic activities. These biological studies proved that compounds 17c/18c against bacterial and 18c/20c against fungal strains exhibited promising antimicrobial activities whereas 17c/19c and 18c/19c showed beneficial analgesic and antipyretic profiles, respectively, at a concentration of 60 mg/kg and were also found to be more potent than the reference drug.

Graphical abstractA new class of N-(N-methylpiperazinoacetyl)-2,6-diarylpiperidin-4-ones were explored for their antimicrobial, analgesic and antipyretic activities. Structure–activity relationship concluded that incorporation of electron withdrawing or donating substituents at the para position of phenyl groups besides the substituents at C-3 and/or C-5 positions exerted beneficial biological and pharmacological profiles.Figure optionsDownload full-size imageDownload as PowerPoint slide