Current Organic Synthesis

Eduardo A. Castro
Universidad Nacional de La Plata
Buenos Aires


Electrogenerated Base Induced Dehydrodimerization and Dehydrotrimerization of Pyrazolones

Author(s): Wei-Cui Li, Zheng-Zheng Zhang, Cheng-Chu Zeng, Li-Ming Hu and Hong-Yu Tian

Affiliation: College of Life Science & Bioengineering, Beijing University of Technology, Beijing 100124, China.

Keywords: Dehydrodimerization, dehydrotrimerization, electrogenerated bases, homocoupling, pyrazolone.

Graphical Abstract:


Electrogenerated base induced dehydrocoupling of pyrazol-5-ones was investigated. The results showed that dehydrodimers and dehydrotrimers were generated simultaneously under electrolytic conditions, and their ratio was mainly dependent on the reaction temperature and the nature of the supporting electrolyte. It was observed that the formation of dimer 2 is preferred at lower temperatures and that trimer 3 is preferentially formed at higher temperatures. In addition, higher yields of 3 could be obtained when NaI was used as the supporting electrolyte. The dehydrocoupling reaction of pyrazol-5-ones to form dimer 2 and trimers 3 and 4 was proposed to be through an EGB-induced cascade mechanism.

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Article Details

Page: [454 - 460]
Pages: 7
DOI: 10.2174/15701794113109990002