Polycyclic N-heterocyclic compounds. 48. syntheses of furo[2,3-h]-[1,6]naphthyridine and imidazo(or pyrimido)[2,1-f]-[1,6]naphthyridines with rearrangement

The formation of a novel ring system, furo2,3-h]1,6]naphthyridine via the Smiles rearrangement and intramolecular cyclization is described. Cyclization of 5-(ω-hydroxyalkylamino)-8-methyl-1,2-dihydrofuro2,3-h]1,6]naphthyridines provided novel spiro compound with rearrangement.