Bisindoles. 38. Synthesis of Some Derivatives of 1H,6H-Indolo[7,6-g]indole

1H,6H,2,3,7,8-Tetramethylindolo[7,6-g]indole and 1H,8H,2,3,4,5,9,10,11,12-octahydrocarbazolo[3,2-c]carbazole were synthesized by the condensation of 1,5-naphthylenedihydrazine with alkyl ketones followed by cyclization of the obtained hydrazones without isolation. The respective N,N-dibenzyl derivatives were obtained by benzylation of the alkyl-substituted compounds. A new spirocyclic system was synthesized by nucleophilic addition of 2,3,3,7,8,8-hexamethylindolenino[7,6-g]indolenine to 2',3'-dimethoxycarbonylspirofluorenecyclopropene.