title: Pyrido(2,3-d)pyrimidines. IV. Synthetic studies leading to various oxopyrido(2,3-d)pyrimidines.
mesh_terms: D055598:Chemical Phenomena; D002621:Chemistry; D008722:Methods; D011728:Pyridones / Q000138:chemical synthesis*; D011743:Pyrimidines / Q000138:chemical synthesis*; D012997:Solvents
chemical_list: D011728:Pyridones; D011743:Pyrimidines; D012997:Solvents