1, 9-substituted fluorenes

Syntheses of 3-chloropyridazino[4, 5, 6-m, l]fluorene and its 9-methyl and 9-chloro derivatives are described. Products in which a chlorine atom of these compounds is exchanged with NH₃, C₆H₅NH₂, NH₂ · NH₂, H₂O, C₆H₅NHNH₂, CH₃ONa, and compounds containing an active methylene group are prepared. Treatment of 3-hydrazinopyridazino[4, 5, 6-m, 1]fluorene and 3-hydrazino-9-methylpyridazino[4, 5, 6-m, 1]fluorene with alcoholic alkali and HgO give respectively pyridazino[4, 5, 6-m, 1]fluorene and 9-methylpyridazino[4, 5, 6-m, 1]fluorene, while 3-phenylhydrazinopyridazino[4, 5, 6-m, 1]fluorene is oxidized under the same conditions to 3-phenylazopyridazino[4, 5, 6-m, 1]fluorene.For Part II see [1].