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

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, methoxy, and benzyloxy;
• R3 is selected from the group consisting of hydrogen and methyl;
• and
• R4 is selected from the group consisting of hydrogen and methyl;
• wherein R1 and R2 are not both H.

A method of preparing a compound having the formula 4:

• the method comprising:
• mixing equimolar amounts of a substituted aromatic aldehyde having the formula 1, a substituted barbituric acid derivative having the formula 2, and a guanidine hydrochloride having the formula 3 to obtain a first mixture;
• adding a mixture of water and ethanol along with a catalytic amount of Ceric Ammonium Nitrate to the first mixture to obtain a reaction mixture;
• stirring the reaction mixture until reaction completion;
• and
• filtering, washing with aqueous ethanol, and purifying the compound of formula 4, wherein the reaction occurs according to the following formula:
• 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.