Synthesis 2015; 47(22): 3561-3572
DOI: 10.1055/s-0035-1560183
paper
© Georg Thieme Verlag Stuttgart · New York

Regioselective C2- and C8-Acylation of 5,11-Dihydroindolo[3,2-b]carbazoles and the Synthesis of Their 2,8-Bis(quinoxalinyl) Derivatives

Roman A. Irgashev*
a   Postovsky Institute of Organic Synthesis, Ural Division, Russian Academy of Sciences, S. Kovalevskoy Str., 22, Ekaterinburg 620990, Russian Federation   Email: irgashev@ios.uran.ru
b   Ural Federal University named after the First President of Russia B. N. Yeltsin, Mira St. 19, Ekaterinburg 620002, Russian Federation
,
Nikita A. Kazin
a   Postovsky Institute of Organic Synthesis, Ural Division, Russian Academy of Sciences, S. Kovalevskoy Str., 22, Ekaterinburg 620990, Russian Federation   Email: irgashev@ios.uran.ru
,
Grigory A. Kim
a   Postovsky Institute of Organic Synthesis, Ural Division, Russian Academy of Sciences, S. Kovalevskoy Str., 22, Ekaterinburg 620990, Russian Federation   Email: irgashev@ios.uran.ru
,
Gennady L. Rusinov
a   Postovsky Institute of Organic Synthesis, Ural Division, Russian Academy of Sciences, S. Kovalevskoy Str., 22, Ekaterinburg 620990, Russian Federation   Email: irgashev@ios.uran.ru
b   Ural Federal University named after the First President of Russia B. N. Yeltsin, Mira St. 19, Ekaterinburg 620002, Russian Federation
,
Valery N. Charushin
a   Postovsky Institute of Organic Synthesis, Ural Division, Russian Academy of Sciences, S. Kovalevskoy Str., 22, Ekaterinburg 620990, Russian Federation   Email: irgashev@ios.uran.ru
b   Ural Federal University named after the First President of Russia B. N. Yeltsin, Mira St. 19, Ekaterinburg 620002, Russian Federation
› Author Affiliations
Further Information

Publication History

Received: 20 June 2015

Accepted after revision: 27 July 2015

Publication Date:
27 August 2015 (online)


Abstract

An efficient approach for the double acetylation of 5,11-dihexyl-6,12-di(hetero)aryl-substituted 5,11-dihydroindolo[3,2-b]carbazoles with acetic anhydride in the presence of boron trifluoride etherate has been developed, thus affording the corresponding 2,8-diacetyl derivatives in good yields. A similar acylation has been shown to occur by the reaction of anhydrides of other carboxylic acids. Oxidation of the obtained 2,8-diacetyl derivatives with selenium dioxide takes place on heating or under microwave irradiation, thus resulting in the formation of the corresponding 2,8-diglyoxals. The latter proved to react with aromatic o-diamines to afford new indolo[3,2-b]carbazoles bearing quinoxalinyl fragments at C-2 and C-8. Major optical properties of quinoxaline-containing indolo[3,2-b]carbazoles have been measured.

Supporting Information