2-Amino-3,5-dinitro-1,8-naphthyridine amination

The compounds 87a and 87b are aminated at position 4, yielding the 4-amino compound (88a, 40%) and the 2,4-diamino compound (88b, 11%) respectively the 2-ethoxy compound (87c), however, undergoes amination at position 4 as well at position 5, giving a mixture of the 4-amino compound (88c, 20%) and the 5-amino compound (89a, 14%).Tlie 2-chloro compound (87d) yields a highly complex reaction mixture from which the 5-amino compound (89b), the 2,4-diamino derivative (88b), and 2,5-diamino-l,8-naphthyridine (89c) could be isolated. l-Ethyl-3-nitro-l,8-naphthyridin-2(lH)-one (90a) and 3,6-dinitro-l-ethyl-l,8-naphthyridin-2(lH)-one (90b) were aminated exclusively in the 4-position to give compounds 91a (62%) and 91b (45%), respectively (93LA471). 

Oxidative amination of the easily accessible 2-R-3,5-dinitro-l,8-naphthyridines only takes place at C-4. With R = H, 4-amino-3,5-dinitro-... 

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