5-(SUBSTITUTEDPHENYL)-7-THIOXO-7,8-DIHYDROPYRIMIDO[4,5-d]PYRIMIDINE-2,4(1H,3H)-DIONE ANALOGUES AS ANTIBACTERIAL AGENTS

A method of treating a microbial infection in a patient, comprising administering to a patient in need thereof a therapeutically effective amount of a compound having the formula 4:

• or a pharmaceutically acceptable salt, ester, stereoisomer, or solvate thereof, wherein:
• R1 is selected from the group consisting of hydrogen, hydroxy, and benzyloxy;
• R2 is selected from the group consisting of hydrogen, a C1-C6 straight or branched chain alkoxy, and benzyloxy;
• R3 is selected from the group consisting of hydrogen and a C1-C6 straight or branched chain alkyl;
• and
• R4 is selected from the group consisting of hydrogen and a C1-C6 straight or branched chain alkyl,
• wherein the microbial infection is caused by Staphylococcus aureus, Bacillus subtilis, Escherichia coli, Pseudomonas aeruginosa, Aspergillus flavus, Trichoderma atroviride, Penicillium citrinum, or Candida albicans.