Heterocyclic Analogs of 5,12-Naphthacenequinone 14 * . Synthesis of naphtho[2,3- f ]indole-3-carboxylic Acid Derivatives

3-carboxylate by using vicarious substitution of hydrogen, followed by intramolecular reductive heterocyclization. Some chemical properties of the target compound were characterized. As observed for the first time in the series of linear hetaryl-fused anthraquinones, the alkylation of hydroxy groups in naphtho[2,3-f]indole-5,10-diones gave not only 4,11-dialkoxy derivatives, but also the isomeric 5,10-dialkoxy derivatives of naphtho[2,3-f]indole-4,11-dione.