Synthesis and antimicrobial screening of 5-(4,7-dimethyl-2-oxo-2H- benzopyran- 6-ylazo)-2-methyl-6- morpholin-4-yl-2, 3-dihydro-3H-pyrimidin-4-one and 5-(4,7-dimethyl-2-oxo-2H- benzopyran-6-ylazo)- 2-methyl-6-piperidin-1-yl-2,3- dihydro-3H-pyrimidin-4-one

Abstract

The coupling reaction of the diazonium solution of the 6-aminocoumarins (1a-c) with malononitrile affords the corre-sponding 2-[(4,7-dimethyl-2-oxo-2H-benzopyran-6-yl)- hydra-zono]-malononitrile (2a-c) which on refluxing with morpholine and piperidine separately yields the corresponding 3-amino-2-(4,7-dimethyl-2-oxo-2H-benzopyran- 6-ylazo)-3-morpholin-4-yl-acrylonitrile (3a-c) and 3-amino-2-(4,7-dimethyl-2-oxo-2H-benzopyran-6- ylazo)-3-piperidin-1-yl-acrylonitrile (3d-f) respec-tively. The enaminonitrile derivatives (3a-f) on heating with ace-tic anhydride give the corresponding 5-(4,7-dimethyl-2-oxo-2H-benzopyran-6-ylazo)- 2-methyl-6-morpholin-4-yl-2,3-dihydro-3H- pyrimidin-4-one and 5-(4,7-dimethyl-2-oxo-2H-benzopyran-6-ylazo)- 2-methyl-6-piperidin-1-yl-2,3-dihydro-3H- pyrimidin-4-one (4a-f). The structures of the compounds (2a-c), (3a-f) and (4a-f) have been established on the basis of spectral and analytical data. All the above compounds have been screened for their antimicro-bial activities and are found to possess significant antibacterial activities.