Synthesis 2005(14): 2357-2366  
DOI: 10.1055/s-2005-870011
PAPER
© Georg Thieme Verlag Stuttgart · New York

A Novel Fragmentation of 7-Azabicyclo[2.2.1]hepta-2,5-dienes: Synthesis of cis-5-Amidino-pyrrolidine-2-acetic Acid Derivatives

Dirk Webera,, Eberhard Hellera,, Christoph Hoenkeb, Stefan Hörerb, Peter Bäuerlea, Volkhard Austel*a
a Abteilung Organische Chemie II, Universität Ulm, Albert-Einstein-Allee 11, 89081 Ulm, Germany
e-Mail: volkhard.austel@chemie.uni-ulm.de;
b Boehringer Ingelheim Pharma GmbH & Co. KG, Abteilung Chemische Forschung, Abteilung Leitstrukturfindung, Birkendorferstr. 65, 88397 Biberach, Germany
Further Information

Publication History

Received 22 February 2005
Publication Date:
13 July 2005 (online)

Abstract

A new fragmentation reaction of 3-bromo-7-azabicy­clo[2.2.1]hepta-2,5-diene carboxylic esters with 2-amino or 2-aminomethyl anilines is described. It leads to cis-5-(benzimidazol-2-yl)- or cis-5-(3,4-dihydroquinazolin-2-yl)-pyrroline-2-acetic acid esters. Substituents on the nitrogen atoms or in the aromatic ring are tolerated as long as they do not strongly reduce the nucleophilicity of the nitrogen atoms. The primary reaction products are not very stable but hydrogenation of the pyrroline and/or cleavage of the ester give products that are suitable for subsequent structural modifications, particularly ones that are interesting for combinatorial syntheses.

1

Present address: CarboGen AG, Neulandweg 5, 5502 Hunzenschwil, Switzerland.

2

Present address: Institut für Pharmazie und Lebensmittelchemie, Universität Würzburg, Sanderring 2, 97070 Würzburg, Germany.

26

Heller, E.; Kurz, G. unpublished experiments.