Synthesis 2009(7): 1195-1203  
DOI: 10.1055/s-0028-1087995
PAPER
© Georg Thieme Verlag Stuttgart ˙ New York

2-(Benzoylimino)thiazolidin-4-ones: Formation by an Alternative Ring Closure and Analysis of Rotational Barriers

Hans-Georg Häckera, Paul W. Elsinghorsta, Susanne Michelsa, Jörg Danielsb, Gregor Schnakenburgb, Michael Gütschow*a
a Pharmaceutical Institute, Pharmaceutical Chemistry I, University of Bonn, An der Immenburg 4, 53121 Bonn, Germany
Fax: +49(228)732567; e-Mail: guetschow@uni-bonn.de;
b Institute of Inorganic Chemistry, University of Bonn, Gerhard-Domagk-Str. 1, 53121 Bonn, Germany
Further Information

Publication History

Received 23 October 2008
Publication Date:
06 March 2009 (online)

Abstract

The reactions of N-benzoyl-N′-(o-cyanoaryl)thioureas with ethyl bromoacetate under alkaline conditions led to the form­ation of either fused 2-(alkylsulfanyl)-4-aminopyrimidines or 2-(benzoylimino)-3-(o-cyanoaryl)thiazolidin-4-ones. The accurate application of slightly different reaction conditions allowed us to adjust the balance between the formation of the pyrimidine or thiazolidine heterocycles. Atropisomerism in the 3-(o-cyanoaryl)thiazolidin-4-ones was influenced by the size of the o-cyanoaryl ring, which was investigated by means of NMR measurements and theoretical calculations.

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Complete bond length and angles, coordinates, and displacement parameters of 3a, 4a, 4b, and 4g have been deposited at the Cambridge Crystallography Data Centre (CCDC numbers 706312, 706313, 706314, and 706315).

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See: http://pwe.no-ip.org/other/pes-results (July 28, 2008).

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PyMOL Molecular Graphics System 0.99: http://www.pymol.org (February 12, 2008).