In the present work the synthesis of various 4-aryl-2-(coumarin-3-yl)-6-(4-methyl-3-phenyl coumarin-6-yl)pyridines (6a-i) and 4-aryl-2-(coumarin-3-yl)-6-(4-methyl-7-methoxy coumarin-8-yl)pyridines (7a-i) have been carried out by reacting 1-[2(H)-1-benzopyran-3-yl]-3-aryl-prop-2-en-1-ones (coumarinoyl chalcones) (3a-f) with appropriate coumarinoyl methyl pyridinium bromide salt 4 and 5 respectively. The target compounds were characterized by the IR, 1 H-NMR, 13 C-APT and mass spectral analysis. Preliminary examination of target compounds as antimicrobial agents has been carried out using Broth dilution method.

A series of novel [1,2,3]-triazolyl substituted benzo [c] coumarins have been synthesized by reacting various 3-coumarinoyl methyl pyridinium bromide salts with 1-(5-methyl-1-phenyl-1H-1,2,3-triazol-4-yl) ethanones in the presence of sodium acetate in refluxing acetic acid. The structures of the synthesized compounds have been elucidated by IR, 1H-NMR, 13C-NMR and Mass spectral data. All the synthesized compounds have been screened for their invitro anti-bacterial and anti-fungal activities. Some of the compounds have been found to be active against some bacterial and fungal pathogens compared to standard drugs.

Background: The 1,2,3-triazole, pyrazole and coumarin based derivatives have received much attention due to their wide coverage of biological properties. The present work describes the microwave synthesis of novel triazolyl pyrazolyl pyrazoline substituted coumarins. Structure of all the newly synthesized compounds are characterized by spectral analysis and screened for their in vitro antimicrobial activity by Broth dilution method. Methods: In synthetic method , the targets were prepared by reaction of various 3-{3-[3-(5-methyl-1-aryl-1H-1,2,3-triazol-4-yl)-1-phenyl-1H-pyrazol-4-yl]acryloyl} coumarins (coumarin chalcones) (3a-d) with hydrazine hydrate or aryl hydrazine(5a-c) in the presence of acetic/propionic acid under microwave irradiation. Results: The structures of all the synthesized compounds were established by IR, 1H-NMR, 13C-APT and selected mass spectral data. The target compounds were also screen for their in vitro antimicrobial efficiency against representative panel of pathogenic strains specifically Gram-positive bacteria (Staphylococcus aureus, Bacillus subtilis), Gram-negative bacteria (Escherichia coli, Salmonella typhi) and Fungi (Candida albicans, Aspergillus niger). Conclusion: In conclusion ,the target compounds were obtained by Microwave Irradiation (MWI) technique in good yield with short reaction time. Among all the synthesized compounds ,4c,4h,6a,6h and 6l were found to have significant activity against bacterial and fungal strains.

Abstract.A series of novel [1,2,3]-triazolyl substituted benzo[c]coumarins have been synthesized by reacting various 3-coumarinoyl methyl pyridinium bromide salts with 1-(5-methyl-1-phenyl-1H-1,2,3-triazol-4-yl)ethanones in the presence of sodium acetate in refluxing acetic acid. The structures of the synthesized compounds have been elucidated by IR, 1 H-NMR, 13 C-NMR and Mass spectral data. All the synthesized compounds have been screened for their in vitro anti-bacterial and anti-fungal activities. Some of the compounds have been found to be active against some bacterial and fungal pathogens compared to standard drugs.