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Article
Synthesis of Condensed Benzo[N,N]-Heterocycles by Microwave-Assisted Solid Acid Catalysis
Catalysis Letters (2008)
  • Shainaz M. Landge, Georgia Southern University
  • Béla Török, University of Massachusetts
Abstract
The synthesis of several types of condensed benzo[N,N]-heterocycles such as benzimidazoles, benzodiazepines, quinoxalinones by a microwave-assisted solvent-free solid acid catalyzed method is described. The commercially available, inexpensive K-10 montmorillonite is an excellent catalyst for the synthesis of the target compounds. Our approach is based on the reactions of a wide variety of o-phenylenediamines, with ketones, aldehydes and bifunctional reagents, respectively. The cyclization reactions were initiated by microwave irradiation. The products, in most cases, were obtained in very high yields (up to 98%) and excellent selectivities in very short reaction times. The effective combination of solid acid catalysis, solvent-free conditions and microwave irradiation provides an attractive and highly ecofriendly approach for the synthesis of these important heterocycles.
Keywords
  • Condensation,
  • Cyclization,
  • o-Phenylenediamines,
  • Microwave,
  • Montmorillonite K-10
Disciplines
Publication Date
2008
Citation Information
Shainaz M. Landge and Béla Török. "Synthesis of Condensed Benzo[N,N]-Heterocycles by Microwave-Assisted Solid Acid Catalysis" Catalysis Letters 122.3-4 (2008): 338-343.
doi:10.1007/s10562-007-9385-1