Fused quinoline heterocycles I. First example of the 2,4-diazidoquinoline-3-carbonitrile and 1-aryl-1,5-dihydro-1,2,3,4,5,6-hexaazaacephenanthrylenesring systems

4-Alkylamino-2-chloroquinoline-3-carbonitriles 2a-f react with hydrazine hy drate to give, in each case, the corresponding 3-amino-4-hydrazino-1H-pyraz olo[3,4-b]quinoline 7. Diazotization of 7 leads to the formation of 2,4-dia zidoquinoline-3-carbonitrile 8, a new heterocyclic ring system. The azidoqu inoline 8 can be converted to the corresponding aminoquinolines 14, and 15 and 16, by reaction with morpholine and sodium dithionite, respectively. On the other hand, 3-amino-4-arylamino-1H-pyrazolo[3,4-b]quinolines 4g-j were prepared by reaction of 4-arylamino-2-chloroquinoline-3-carbonitriles 2g-j with hydrazine hydrate at 50-60 degrees C. Diazotization of 4g-j afforded the novel tetracyclic ring system 1-aryl-1,5-dihydro-1,2,3,4,5,6-hexaazaace phenanthrylenes 5g-j.