Abstract
New coumarin derivatives namely (5-oxo-chromeno[3,2-c] dihydropyran derivatives 2a,b, 3a,b),(3 -acetyl-4-aryl -2-methy1-5-oxo-chromeno[3,2-c]2,3,4-trihydropyran 4a,b), ( 2-amino-5-oxo-4H,5H-pyrano[3,2-c]chromene-3-carbonitrile 5a,b and 2-amino-5-oxo-3,4,4a,10b-tetrahydro-2H,5H-pyrano[3,2-c]chromene-3-carboxylic acid amide 6a,b) were synthesized starting from 3-arylidene chromen-2,4-dione derivatives. The structures of the obtained compounds were confirmed by analytical elemental analysis, IR, 1H-NMR and mass spectra. The new compounds were screened for their antibacterial activity. Compound 3a was the most active compound against gram positive and gram negative bacteria.