Synthesis of 1-Amino-3-oxo-2,7-naphthyridines via Smiles Rearrangement: A New Approach in the Field of Chemistry of Heterocyclic Compounds.

In this paper we describe an efficient method for the synthesis of new heterocyclic systems: furo[2,3- c ]-2,7-naphthyridines 6 , as well as a new method for the preparation of 1,3-diamino-2,7-naphthyridines 11 . For the first time, a Smiles rearrangement was carried out in the 2,7-naphthyridine series, thus gaining the opportunity to synthesize 1-amino-3-oxo-2,7-naphthyridines 4 , which are the starting compounds for obtaining furo[2,3- c ]-2,7-naphthyridines. The cyclization of alkoxyacetamides 9 proceeds via two different processes: the expected formation of furo[2,3- c ]-2,7-naphthyridines 10 and the 'unexpected' formation of 1,3-diamino-2,7-naphthyridines 11 ( via a Smiles type rearrangement).