Synthesis and Antimicrobial Activity of Some New Coumarin Incorporated Pyridine-3-carbonitrile Derivatives

Abstract

Drug resistance causes serious difficulties in the routine therapy for curing common microbial infections. Thus it is very essential to develop new antimicrobial agents which can offer alternative treatments. The development of potent and effective antimicrobial agents is of utmost importance to overcome the emerging multidrug resistance strains of bacteria and fungi. The technique involves Knoevenagel reaction between substituted salicylaldehyde and ethyl acetoacetate in presence of piperidine as catalyst to give 3-acetyl coumarin. The intermediate coumarinyl chalcones was synthesized by condensing with various substituted benzaldehyde in presence of ethanolic KOH. The final synthesized pyridine-3-carbonitrile derivative was prepared upon refluxing with coumarinyl chalcones with malononitrile in presence of ammonium acetate. All the newly synthesized compounds were assigned on the basis of IR, 1H NMR and mass spectral data.  The finalsynthesized compounds were screened for their antibacterial activity tube dilution method. Most of the compounds showed promising MIC by tube dilution method as compared to standard Cephalosporin.