Synthesis, Characterization, andIn VitroAntimicrobial Activity of a New Class of 7-Substituted Amino-2-phenyl-3H-pyrimido[4,5-d]pyrimidin-4-one

A new class of pyrimido pyrimidine derivatives that exhibits in vitro antimicrobial activity was synthesized. The protection of amino group in the compound 1 with acetic anhydride, followed by the reaction with POCl3, gave 3. The reaction of 3 with different substituted phenyl methanediamine in dry TEA under inert atmosphere led to the formation of 4. Deprotection of 4 followed by refluxion with different acid chlorides yielded title compounds 6a, 6b, 6c, 6d, 6e, 6f, 6g, 6h, 6i, 6j, 6k, 6l, 6m in good yields. The identities of these compounds were confirmed following elemental analysis, IR, 1H, 13C NMR, and mass spectral studies. All the title compounds exhibited pronounced in vitro antibacterial and antifungal activities.