Synthesis of some 2-thioxopyrido[2,3-d]pyrimidine ribofuranosides and their antimicrobial activity

2-Thioxo-3,5,7-trisubstituted-1-[2',3',5'-tri-O-benzoyl-beta -D-ribofuranosyl]pyrido [2,3-d]pyrimidin-4(1H)-ones have been prepared by the condensation of trimethylsilyl derivative of w2-thioxo-3,5,7-trisubstituted pyrido[2,3-d]pyrimidin-4(IH)-ones with P-D-ribofuranose 1-acetate-2,3,5-tribenzoate in 65%-78% yield. The structure of the synthesized ribofuranosides and their precursors have been established by JR, H-1 NMR and elemental analysis. These derivatives, have been screened for their antimicrobial activity.