New route to the synthesis of the indolo[7,6-g]indole (“bis(pyrrolo)naphthalene”) system starting from 1,5-dihydroxynaphthalene

✍ Scribed by Jadwiga Sołoducho

• Publisher: Elsevier Science
• Year: 1999
• Tongue: French
• Weight: 138 KB
• Volume: 40
• Category: Article
• ISSN: 0040-4039
• DOI: 10.1016/s0040-4039(99)00121-5

✦ Synopsis

A short and convenient route for the synthesis of indolo [7,6-g]indole derivatives starting from dihydroxynaphthalene is described. 1,5-Dihydroxynaphthalene (1) after alkylation, nitration and reduction gave 4,8diamino-l,5-dibutoxynaphthalene (4). After reaction with iodine, 4,8-diamino-l,5-disubstituted naphthalene gave the corresponding 3,7-diodonaphthalene (5) in nearly quantitative yields. Palladium-catalyzed reaction of this diiodonaphthalene derivative with (trimethylsilyl)acetylene (TMSA), followed by efficient CuI-mediated eyclization with simultaneous elimination of the TMS substituent, allov, ed an efficient preparation of 5,10-dibutoxyindolo[7,6-g]indole (8).