Reactions of Nitro-1,8-Naphthyridines

The halogenolysis of a nitro-1,5-naphthyridine (using phosphorus pentachloride) has been recorded in Section 3.1.2. The reduction of nitro-1,5-naphthyridines to 

The physical and biological properties of these important derivatives have been widely investigated, usually for comparison with those of isomeric or related systems. 

There is infrared spectral evidence that l,5-naphthyridin-2-amine may exist (at least in the solid state) as its l,5-naphthyridin-2(lH)-imine tautomer (9),148 but confirmation of this unexpected postulate by other means has not been forthcoming. The ionization constants of 1,5-naphthyridinamines have been compared with those of comparable 1,6-naphthyridinamines 331 the mass spectra of several 1,5-naphthyridinamines have been compared with those of a variety of other heterocycles 434  

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