Synthesis and antimicrobial activity of coumarin pyrazole pyrimidine 2,4,6(1H,3H,5H)triones and thioxopyrimidine4,6(1H,5H)diones

A series of 5-((3-(2-oxo-2H-chromen-3-yl)-1-phenyl-1H-pyrazol-4-yl)methylene)pyrimidine-2,4,6(1H,3H,5H)-trione (4a-f) and dihydro-5-((3-(2-oxo-2H-chromen-3-yl)-1-phenyl-1H-pyrazol-4-yl)methylene)-2-thioxopyrimidine-4,6(1H,5H)-dione (5a-f) derivatives were synthesized by the condensation of 3-(2-oxo2H-chromen-3-yl)-1-phenyl-1H-pyrazole-4-carbaldehyde (3a-f) with barbituric acid and thiobarbituric acid in acetic acid under microwave irradiation method. The newly synthesized compounds were evaluated for their antibacterial activity against Bcillus subtilis, Staphylococcus aureus, Staphylococcus epidermidis, Escherichia coli, Pseudomonas aeoginosa, and Klebsiella pneumoniae. All the compounds were found to be moderately active against used microorganisms, whereas compounds (4d) and (4e) exhibited good antifungal activity against Aspergillus niger.