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-hexaazaacephenanthrylenes ring systems

Abstract

4-Alkylamino-2-chloroquinoline-3-carbonitriles 2a–f react with hydrazine hydrate to give, in each case, the corresponding 3-amino-4-hydrazino-1H-pyrazolo[3,4-b]quinoline 7. Diazotization of 7 leads to the formation of 2,4-diazidoquinoline-3-carbonitrile 8, a new heterocyclic ring system. The azidoquinoline 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 °C. Diazotization of 4g–j afforded the novel tetracyclic ring system 1-aryl-1,5-dihydro-1,2,3,4,5,6-hexaazaacephenanthrylenes 5g–j.