Synthesis and antimicrobial screening of some new 4-imino-3,5,7-trisubstituted pyrido[2,3-d]pyrimidines and their ribofuranosides as potential chemotherapeutic agents

Some new nucleosides, viz. 4-imino-3,5,7-trisubstituted-1-(2',3',5'-tri-O-benzyl-beta-D-ribofuranosyl)pyrido[2,3-d]pyrimidin/e-2(1H)-ones/ thiones(VII/VIII), have been synthesized by condensation of trimethylsilyl derivatives of 4-imino-3,5,7-trisubstituted pyrido[2,3d]pyrimidin/e-2(1H)-ones/thiones (III/IV) with beta-D-ribofuranosyl-1-acetate-2,3,5-tribenzoate. Compounds III/IV have been synthesized by refluxing 2-amino-3-cyano-4,6-disubstituted pyridine (II) with substituted an arylisocyanate or an isothiocyanate respectively. The structure of all the synthesized compounds have been established by IR and H-1 NMR studies. These compounds have been screened for antimicrobial activities in order evaluate. The possibility of the derivatives to be used as potential chemotherapeutic agents.