Background: Coumarin belongs to a group known as benzopyrones which consist of a benzene
ring joined to a pyrone nucleus which possesses varied biological activities. The current work described
the Microwave-assisted synthesis of various pyridyl pyrazoline substituted coumarins. These
newly formed coumarin derivatives are characterized by spectra analysis and screened for their in
vitro antimicrobial screening against bacterial and fungal pathogens by Broth dilution method.
Methods: In the synthetic method, the target compounds were synthesized by reacting different coumarin
chalcones with hydrazine hydrate in acetic acid or propionic acid and phenylhydrazine derivatives
in acetic acid respectively with the help of microwave irradiation method.
Results: The structures of all the synthesized compounds were established by IR, 1H-NMR, 13C-APT
and some representative mass spectral data. The target compounds were also screened for their in vitro
antimicrobial screening against a representative panel of bacteria (Bacillus subtilis, Staphylococcus
aureus, Escherichia coli and Salmonella typhi) and fungi (Aspergillus niger and Candida albicans).
Conclusion: In conclusion, the final products were obtained by utilizing Microwave Irradiation
(MWI) technique in excellent yields with a short reaction time. Among all the synthesized compounds,
3a, 3d, 7a and 7c were found to have significant activity against bacterial and fungal strains.