Synthesis 2005(1): 131-135  
DOI: 10.1055/s-2004-834923
PAPER
© Georg Thieme Verlag Stuttgart · New York

ω-Functionalized 3-Alkynylpyrazolo[1, 5-a]pyrimidines by Sonogashira Coupling

Lunxiang Yin, Jürgen Liebscher*
Institut für Chemie, Humboldt-Universität Berlin, Brook-Taylor-Straße 2, 12489 Berlin, Germany
Fax: +49(30)20937552; e-Mail: liebscher@chemie.hu-berlin.de;
Further Information

Publication History

Received 7 July 2004
Publication Date:
17 November 2004 (online)

Abstract

ω-Functionalized 3-alkynylpyrazolo[1,5-a]pyrimidines were synthesized via the Pd-C/CuI/PPh3-catalyzed Sonogashira coupling of 3-iodopyrazolo[1,5-a]pyrimidines with propargylic and homopropargylic compounds. Subsequent Pd-C-catalyzed hydrogenation of the C-C triple bond afforded 3-(3-dimethylaminopropyl)-pyrazolo[1,5-a]pyrimidines.