title: Pyrido (2,3-d) pyrimidines. II. Synthesis of ribonucleosides of 4-oxo- and 2,4-dioxopyrido (2,3-d) pyrimidines.
mesh_terms: D007659:Ketones; D008722:Methods; D008745:Methylation; D008956:Models, Chemical; D011725:Pyridines; D011743:Pyrimidines / Q000138:chemical synthesis*; D012263:Ribonucleosides / Q000138:chemical synthesis*
chemical_list: D007659:Ketones; D011725:Pyridines; D011743:Pyrimidines; D012263:Ribonucleosides