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Microwave‐Assisted Expedite Synthesis of 2‐Phenylimidazo[1,2‐ a ]pyridylquinoxalin‐2(1 H )‐ones
Author(s) -
Sakhuja Rajeev,
Shakoor S. M. Abdul,
Kumari Santosh,
Kumar Anil
Publication year - 2015
Publication title -
journal of heterocyclic chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.321
H-Index - 59
eISSN - 1943-5193
pISSN - 0022-152X
DOI - 10.1002/jhet.2189
Subject(s) - chemistry , montmorillonite , catalysis , pyridine , tetrahydrofuran , microwave , microwave irradiation , medicinal chemistry , organic chemistry , physics , quantum mechanics , solvent
An efficient methodology has been developed for the synthesis of quinoxalin‐2(1 H )‐one derivatives of 2‐phenylimidazo[1,2‐ a ]pyridines by microwave‐irradiated Hinsberg heterocyclization between 2‐phenylimidazo[1,2‐ a ]pyridine‐3‐glyoxalates and o ‐phenylenediamine using either montmorillonite K‐10 or Yb(OTf) 3 as catalysts. Montmorillonite K‐10 was proven to be an efficient catalyst for the heterocyclization reaction between sterically hindered glyoxalate and o ‐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.