Synthesis 2011(20): 3261-3266  
DOI: 10.1055/s-0030-1260198
PAPER
© Georg Thieme Verlag Stuttgart ˙ New York

Synthesis of 4-Quinolones via Cyclocondensation of Substituted ortho-Amidoacetophenones: A Refit to the Camps Cyclization by Applying Trimethylsilyl Trifluoromethanesulfonate/Triethylamine

Christian Eidamshaus, Therese Triemer, Hans-Ulrich Reissig*
Institut für Chemie und Biochemie, Freie Universität Berlin, Takustr. 3, 14195 Berlin, Germany
Fax: +49(30)83855367; e-Mail: hans.reissig@chemie.fu-berlin.de;
Further Information

Publication History

Received 2 July 2011
Publication Date:
01 September 2011 (online)

Abstract

A modification of the classical Camps cyclization is described. A series of substituted 4-quinolone derivatives is prepared via trimethylsilyl trifluoromethanesulfonate/triethylamine induced cyclocondensation of substituted ortho-amidoacetophenones. The process shows a broad substrate scope and allows selective preparation of 2-aryl- and 2-alkyl-substituted 4-quino­lones. Enantiopure starting materials react without loss of optical purity using the modified conditions. Subsequent transformations of the products involving preparation of a 4-quinolyl nonaflate and O-selective methylation are also described.