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

Abstract

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.