Application of Organolithium and Related Reagents in Synthesis, Part XII. Synthesis of Phenyl- and Pyridylpyridopyridazinones and their Derivatives

Article abstract of DOI:10.1007/BF00819523

The preparation of the pyridazinones 10a, 10b, 11a, 11b, and 12a, 12b from the ketoamides 7, 8, and 9 and hydrazine hydrate is described.It was found that from the ketoamides 8b and 9b in addition to the expected pyridopyridazinones 11b and 12b also aminopyridopyridazines 14 and 15 were formed and that ketoamide 7b gave exclusively aminopyridopyridazine 13.The pyridopyridazinones 10b, 11b, and 12b were alkylated with alkyl iodides. Key words: Pyridinecarboxamides; lithiation; benzoylpyridinecarboxamides; pyridinecarbonylpyridinecarboxamides; pyridopyridazinones; aminopyridopyridazines.