PDF herunterladen
Synlett 1997; 1997(6): 679-680
DOI: 10.1055/s-1997-3274
letter
© Georg Thieme Verlag, Rüdigerstr. 14, 70469 Stuttgart, Germany. All rights reserved. This journal, including all individual contributions and illustrations published therein, is legally protected by copyright for the duration of the copyright period. Any use, exploitation or commercialization outside the narrow limits set by copyright legislation, without the publisher's consent, is illegal and liable to criminal prosecution. This applies in particular to photostat reproduction, copying, cyclostyling, mimeographing or duplication of any kind, translating, preparation of microfilms, and electronic data processing and storage.

Regioselective Synthesis of 5-Trifluoromethyl Pyrazoles by the [1+4] Cyclization of Phenylhydrazones with N-Aryl Trifluoroacetimidoyl Iodides

Hong-Bin Yu, Wei-Yuan Huang*
  • *Laboratory of Organofluorine Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, 354 Fenglin Lu, 200032, Shanghai, China, Fax 0086-21 64166128; E-mail: wyhuang@pub.sioc.ac.cn
Weitere Informationen

Publikationsverlauf

Publikationsdatum:
31. Dezember 2000 (online)

 als PDF herunterladen  Lizenzen und Reprints Alle Artikel dieser Rubrik
Preview

Treatment of the phenylhydrazone of a methyl ketone (2) or cyclohexanone (3) with N-aryl trifluoroacetimidoyl iodide (1) in the presence of excess sodium hydride resulted in a [1+4] cyclization to give 5-trifluoromethyl pyrazoles (4, 5) regioselectively. The structure of products 4 or 5 was confirmed by the 13C NMR spectra.

trifluoromethyl - pyrazole - [1+4] cyclization - N-aryl trifluoroacetimidoyl iodide