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Synfacts 2008(8): 0799-0799
DOI: 10.1055/s-2008-1077941
DOI: 10.1055/s-2008-1077941
Synthesis of Heterocycles
© Georg Thieme Verlag
Stuttgart ˙ New York
Synthesis of Pyrazoles by Three-Component One-Pot Process
H.-L. Liu, H.-F. Jiang*, M. Zhang, W.-J. Yao, Q.-H. Zhu, Z. Tang
South China University of Technology, Guangzhou, P. R. of China
Further Information
Publication History
Publication Date:
23 July 2008 (online)
Significance
The one-pot synthesis of pyrazoles by Sonogashira-type reaction of acyl chlorides 1 with substituted acetylenes 2, followed by cyclocondensation in presence of various hydrazines 3 is reported. The procedure is rather simple and convenient; however, it requires optimization, and preparative yields vary from poor to excellent. The method may be used for pyrimidine synthesis as well, as shown for a single example. In this case acetamidine hydrochloride 7 serves as a third coupling reagent.