Electrochemical oxidation of catechols in the presence of ethyl-2-chloroacetoacetate. Synthesis and mechanistic study

✍ Scribed by Mojtaba Shamsipur; Saied Saeed Hosseiny Davarani; Davood Nematollahi

• Publisher: Journal of Heterocyclic Chemistry
• Year: 2006
• Tongue: English
• Weight: 436 KB
• Volume: 43
• Category: Article
• ISSN: 0022-152X
• DOI: 10.1002/jhet.5570430638

✦ Synopsis

Abstract

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Electrochemical oxidation of catechol and some of 3‐substituted catechols (1a‐c) has been studied in the presence of ethyl‐2‐chloroacetoacetate (3) in water/acetonitrile (90:10) solution using cyclic voltammetry and controlled‐potential coulometry. The results indicate that the quinones derived from catechols (1a‐c) participate in Michael addition reactions with ethyl‐2‐chloroacetoacetate(3), with consumption of only two electrons per molecule of 1, to form the corresponding benzofurans (10a‐c). The electrochemical synthesis of benzofurans (10a‐c) has been successfully performed at a carbon rod electrode and in an undivided cell with good yields and purity. A new two‐electron mechanism for the electrode process is proposed.