Synthesis of pyrrolo[3,2- a]phenazines from 5-nitroindoles and anilines

Zbigniew Wróbel; Michał Więcław; Robert Bujok; Krzysztof Wojciechowski

doi:10.1007/s00706-013-1087-3

Synthesis of pyrrolo[3,2- a]phenazines from 5-nitroindoles and anilines

Monatsh Chem. 2013;144(12):1847-1853. doi: 10.1007/s00706-013-1087-3. Epub 2013 Oct 10.

Authors

Zbigniew Wróbel¹, Michał Więcław², Robert Bujok¹, Krzysztof Wojciechowski¹

Affiliations

¹ Institute of Organic Chemistry, Polish Academy of Sciences, ul. Kasprzaka 44/52, P.O. Box 58, 01-224 Warsaw, Poland.
² Department of Chemistry, Warsaw University of Technology, ul. Noakowskiego 3, 00-664 Warsaw, Poland.

Abstract

Abstract: Anilines react with 5-nitroindoles in the presence of t-BuOK in N,N-dimethylformamide (DMF) to form 5-nitroso-4-arylaminoindoles that in turn when treated with N,O-bis(trimethylsilyl)acetamide cyclize to pyrrolo[3,2-a]phenazines. In an alternative approach pyrrolo[3,2-a]phenazines are formed from aminoindoles and nitroarenes.

Keywords: Amines; Anions; Cyclizations; Heterocycles; Lewis acids; Nucleophilic substitutions.