Abstract The preparation of some 3, 7-disubstituted-5, 6-dihydroquino [3, 2-c][1, 8] naphthyridines (6) by the condensation of 7-substituted-2, 3-dihydro-1, 8-naphthyridin-4- (1H) ones (5) with o-aminoacetophenone or o-aminobenzophenone is described. All the 5, 6-dihydroderivatives 6 were transformed into the fully aromatic compounds 7 by heating with nitrobenzene. Only a few quino [3, 2-c][1, 8] naphthyridines were previously described.
