Azepinoindole Synthesis from a 1,2,3,4-Tetrahydro-9(10H)-acridinone and Sodium Dichloroisocyanurate or Singlet Oxygen

Article abstract of DOI:10.1021/jo00257a015

Sodium dichloroisocyanurate (4) acts on 7-methyl-1,2,3,4-tetrahydro-9(10H)-acridinone (1) to give principally either cis-1,2-diol 2 or azepino<1,2-a>indole 3, by suitable choice of reactant proportions. 2,3,6-Trimethyl-4(1H)-quinolinone (6) yields a novel, methylene-bridged, oxygenated dimer 9, while with excess 4 the chief product is the 1,2-dihydro-3H-indol-3-one 7. 6-Methyl-2-phenyl-4(1H)-quinolinone (12) initially gives the 3-chloro derivative 14, which then reacts further with 4, yielding chlorine-free 6-methyl-2-phenyl-4H-3,1-benzoxazin-4-one (16).The sensitized photooxidation of acridinone 1 furnishes azepinoindole 3 en route to dicarboxylic acid 5; upon similar treatment, quinolinone 6 provides the analogous indolone 7.Reaction pathways to account for the results are presented.N-Halo imide 4 offers advantages over the more conventional NaOCl in synthesis as illustrated also with a "one-pot" Hofmann degradation of 4-chlorobenzamide.