A New Route to Ring-Fused Pyrazines:
Imidazo[4,5-b]Quinoxalines by
a Simple Oxidation-Annulation Sequence
Svenja Herzoga, Gunther Buehrdela, Rainer Beckert*a, Susann Klimasa, Ernst-Ulrich Würthwein*b, Stefan Grimmeb, Helmar Görlsc a Institute of Organic and Macromolecular Chemistry, Friedrich-Schiller-University Jena, Humboldtstr.
10, 07743 Jena, Germany Fax: +49(3641)948212; e-Mail: C6bera@uni-jena.de; b Organic-Chemistry Institute, University Münster, Corrensstr.
40, 48149 Münster, Germany Fax: +49(251)8339772; e-Mail: wurthwe@uni-muenster.de; c Institute of Inorganic and Analytical Chemistry, Friedrich-Schiller-University Jena, Lessingstr.
8, 07743 Jena, Germany
