Autoxidation of 4-Hydrazinylquinolin-2(1 H )-one; Synthesis of Pyridazino[4,3- c :5,6- c ']diquinoline-6,7(5 H ,8 H )-diones.

An efficient synthesis of a series of pyridazino[4,3- c :5,6- c ']diquinolines was achieved via the autoxidation of 4-hydrazinylquinolin-2(1 H )-ones. IR, NMR ( 1 H and 13 C), mass spectral data, and elemental analysis were used to fit and elucidate the structures of the newly synthesized compounds. X-ray structure analysis and theoretical calculations unequivocally proved the formation of the structure. The possible mechanism for the reaction is also discussed.