title: [Syntheses of nitrogen-containing heterocyclic compounds. XXII. Syntheses of pyridonaphthyridines by improved one-step process (author's transl)].
mesh_terms: D009287:Naphthyridines / Q000138:chemical synthesis*; D011728:Pyridones / Q000138:chemical synthesis*
chemical_list: D009287:Naphthyridines; D011728:Pyridones