Get 20M+ Full-Text Papers For Less Than $1.50/day. Start a 14-Day Trial for You or Your Team.

Learn More →

Regiochemical Control of Pyrazoles by Solvent and β‐Enamino Diketone Structure: Regioselective Synthesis of 4,5‐Disubstituted N‐Phenylpyrazoles

Regiochemical Control of Pyrazoles by Solvent and β‐Enamino Diketone Structure: Regioselective... A simple method for the regiocontrolled synthesis of the 4,5‐disubstituted N‐phenylpyrazole regioisomers 2 and 3 from β‐enamino diketones and phenylhydrazine is described. Pyrazole 2 was prepared regioselectively by carrying out the reaction in a protic solvent, whereas pyrazole 3 was obtained as the main product by using an aprotic solvent. Steric factors regarding the β‐enamino diketones also influenced the regiochemistry of 2 and 3. The influence of solvent on the reaction outcome can be rationalized by using Fukui indices. The structures of 2 and 3 were unambiguously elucidated by 1H and 13C NMR spectroscopy, two‐dimensional HMBC experiments, high resolution mass spectrometry, and X‐ray crystallographic analysis. http://www.deepdyve.com/assets/images/DeepDyve-Logo-lg.png Asian Journal of Organic Chemistry Wiley

Regiochemical Control of Pyrazoles by Solvent and β‐Enamino Diketone Structure: Regioselective Synthesis of 4,5‐Disubstituted N‐Phenylpyrazoles

Loading next page...
 
/lp/wiley/regiochemical-control-of-pyrazoles-by-solvent-and-enamino-diketone-U8DbUPqKJK

References (25)

Publisher
Wiley
Copyright
© 2017 Wiley‐VCH Verlag GmbH & Co. KGaA, Weinheim
ISSN
2193-5807
eISSN
2193-5815
DOI
10.1002/ajoc.201700048
Publisher site
See Article on Publisher Site

Abstract

A simple method for the regiocontrolled synthesis of the 4,5‐disubstituted N‐phenylpyrazole regioisomers 2 and 3 from β‐enamino diketones and phenylhydrazine is described. Pyrazole 2 was prepared regioselectively by carrying out the reaction in a protic solvent, whereas pyrazole 3 was obtained as the main product by using an aprotic solvent. Steric factors regarding the β‐enamino diketones also influenced the regiochemistry of 2 and 3. The influence of solvent on the reaction outcome can be rationalized by using Fukui indices. The structures of 2 and 3 were unambiguously elucidated by 1H and 13C NMR spectroscopy, two‐dimensional HMBC experiments, high resolution mass spectrometry, and X‐ray crystallographic analysis.

Journal

Asian Journal of Organic ChemistryWiley

Published: May 1, 2017

Keywords: ; ; ; ;

There are no references for this article.