Microwave‐Assisted Expedite Synthesis of 2‐Phenylimidazo[1, 2‐a]pyridylquinoxalin‐2(1H)‐ones. (31st May 2014)

• Record Type: Journal Article
• Authors: Sakhuja, Rajeev; Shakoor, S. M. Abdul; Kumari, Santosh; Kumar, Anil
• Is Part Of: Journal of heterocyclic chemistry. Volume 52:Number 3(2015)
• Page Start: 773
• Page End: 779
• Publication Date: 2014-05-31
• Subjects: Heterocyclic compounds -- Periodicals; 547.59
• DOI: 10.1002/jhet.2189
• Languages: English
• ISSNs: 0022-152X

Abstract

<abstract abstract-type="main"> <title> <x xml:space="preserve">Abstract</x> </title> <p>An efficient methodology has been developed for the synthesis of quinoxalin‐2(1<italic>H</italic>)‐one derivatives of 2‐phenylimidazo[1, 2‐<italic>a</italic>]pyridines by microwave‐irradiated Hinsberg <named-content content-type="reactionType" xlink:type="simple" xmlns:xlink="http://www.w3.org/1999/xlink">heterocyclization</named-content> between 2‐phenylimidazo[1, 2‐<italic>a</italic>]pyridine‐3‐glyoxalates and <italic>o</italic>‐phenylenediamine using either montmorillonite K‐10 or Yb(OTf)₃ as catalysts. Montmorillonite K‐10 was proven to be an efficient catalyst for the <named-content content-type="reactionType" xlink:type="simple" xmlns:xlink="http://www.w3.org/1999/xlink">heterocyclization</named-content> reaction between sterically hindered glyoxalate and <italic>o</italic>‐phenylenediamine only under microwave conditions. The use of Yb(OTf)₃/tetrahydrofuran was also found to be an effective catalyst for the above chemical transformation among a series of Lewis acids screened under microwave conditions; however, comparatively lesser yields were obtained as compared with the use of montmorillonite K‐10.</p> </abstract>