Synthesis of nucleosides of 5,7-disubstituted pyrido [2,3-d] pyrimidines and their antibacterial activity.

Synthesis of 4-amino-5,7-diphenyl-1-(beta-D-ribofuranosyl)pyrido[2,3-d] pyrimidin-2-ones nucleoside, 4-amino-5,7-disubstituted-1-(beta-D-ribofuranosyl) pyrido [2,3-d] pyrimidin-2-thiones nucleosides, 2-thioxo-3,5,7-triphenyl-1- (beta-D-ribofuranosyl) pyrido [2,3-d] pyrimidin-4 (3H) ones nucleoside and 3,5,7-triphenyl-1-(beta-D-ribofuranosyl) pyrido [2,3-d] pyrimidin-2,4 (3H) diones nucleoside have been reported. The elemental analyses, IR and 1H NMR spectral data confirm the structure of the compounds. The synthesized nucleosides have been tested for antibacterial activity and found to be more active than the pyrido [2,3-d] pyrimidines.