Synthesis of indole-5,6- and carbazole-2,3-dicarboxylic acid functional derivatives

Abstract

Principal synthetic approaches to the synthesis of indole-5,6- and carbazole-2,3-dicarboxylic acid functional derivatives are considered. The first of them consists in the construction of the indole ring from simpler aromatic compounds containing carboxy groups, cyano groups, or an imide fragment with subsequent reductive cyclization of the compounds formed. The second approach is based on the modification of a pyrrole or an indole fragment by the introduction of different functional groups with subsequent intramolecular cyclization to the corresponding heterocycles.