A concise regioselective synthesis of hydroxyazaisoindolinones and their conversion into pyridopyridazinones

Article abstract of DOI:10.1016/0040-4020(95)01109-9

The synthesis of pyridopyridazinones 7 and 8 via the reaction of hydroxyazaisoindolinones 5 and 6 with hydrazine hydrate is described. Compounds 7 and 8 were then subjected to reactions with alkyl halides to furnish N-alkyl derivatives. Only in the reaction of pyridopyridazinone 8 with benzyl bromide was the O-benzylpyridopyridazine 14b formed in addition to the N-benzylpyridopyridazinone 14a.