Abstract

In Iraq like most third world countries, attempts to discover new antibiotic drugs derived from coumarins moreover develop the branch of applied in organic chemistry. Novel coumarin derivatives were synthesized in a good yield through converting lacton to lactam and study the biological activity of the synthesized compounds. Coumarins were characterized by elemental analysis, FT-IR, ¹H-NMR and UV/visible spectra. The novel coumarins have been tested in vitroagainst (gram positive bacteria Staphylococcus aureus and against other gram negative bacteria, such as Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa and Proteus vulgaris; in order to assess their antimicrobial properties. Moreover, charge, bond length, bond angle, twist angle, heat of formation and steric energy were calculated by using of the ChemOffice program. The study indicates that these coumarins have high activity against tested bacteria. Based on the reported results, it may be concluded that the coumarin act as synthons for synthesis of new coumarin derivatives through the replacement of oxygen atom by nitrogen atom.

Key words: Biological activity, coumarins, oxoquinolin, thiourea.