Abstract
5-(2-Oxocyclopentanecarboxamido) quinoline (IVb) was prepared from 5-aminoquinoline (IVa) and 2-carbethoxycyclopentanone (III) and isolated as a crystalline compound. IVb was treated with polyphosphoric acid-xylene to give 4, 11-diazagona-1, 3, 5 (10), 6, 8, 13-hexaen-12-one (I). Two isomers, 4, 11-diazagona-5, 7, 9, 13-tetraen-12-one (II) and 1, 2, 3, 4, 7, 8, 9, 10, 11-nonahydro-4, 11-diazacyclopenta [b] phenanthren-7-one (VI), were synthesized by the reaction of 1, 2, 3, 4-tetrahydro-5-aminoquinoline (Va) and III in the presence of trifluoroacetic acid. 5-(2-Oxocyclopentanecarboxamido)-2-methoxyquinoline (X) could not be cyclized to the expected diazasteroid system under various conditions tested.
