4- Amino-3-nitro-l,5 -naphthyridines

For the same reasons as discussed for the 3-nitro-1,8-naphthyridines, addition at C-4 is strongly promoted. If position 4 is occupied, no addition takes place 4-amino-3-nitro-l,6- and -1,5-naphthyridine do not undergo addition at C-2 when subjected to treatment with liquid ammonia. It is interesting that 46a does not undergo covalent hydration in neutral nor in acidic medium.9... 

Amino-3-nitro-l,8-naphthyridin-5(8H)-one 4-(methylamino)-3-nitro-l,8-naphthyridin-... 

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). 

Ethoxy-1,6-naphthyridine 2-Ethoxy-3-nitro-l,6-naphthyridin-4-amine 2- Ethoxy-3-nitro- 1,6-naphthyridine Ethyl 5-amino-7-benzylseleno-8-cyano-2-methyl-1,6-naphthyridine-3-carboxylate Ethyl 6-amino-2-methyl-5-oxo-5,... 

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