SIMPLE SYNTHESIS OF 2,2'-BISINDOLE FROM INDIGO AND ITS APPLICATION FOR THE SYNTHESES OF INDOLO[2,3-A]PYRROLO[3,4-C]CARBAZOLE-5,7-(6H)DIONE AND -5-(6H)ONE DERIVATIVES
M. Somei et al., SIMPLE SYNTHESIS OF 2,2'-BISINDOLE FROM INDIGO AND ITS APPLICATION FOR THE SYNTHESES OF INDOLO[2,3-A]PYRROLO[3,4-C]CARBAZOLE-5,7-(6H)DIONE AND -5-(6H)ONE DERIVATIVES, Heterocycles, 41(10), 1995, pp. 2161-2164
Indigo was converted to 2,2'-bisindole, from which 6-substituted indol
o[2,3-a]pyrrolo[3,4-c]carbazole-5,7-(6H)dione and -5-(6H)one derivativ
es were prepared in short steps. Bromination of lindolo[2,3-a]pyrrolo[
3,4-c]carbazole5,7-(6H)dione is also reported.