Aqueous synthesis of 1-H-2-substituted benzimidazoles via transition-metal-free intramolecular amination of aryl iodides

Molecules. 2012 Oct 24;17(11):12506-20. doi: 10.3390/molecules171112506.

Abstract

A straightforward method has been developed for the synthesis of the benzimidazole ring system through a carbon-nitrogen cross-coupling reaction. In the presence of 2.0 equiv. of K(2)CO(3) in water at 100 °C for 30 h, the intramolecular cyclization of N-(2-iodoaryl)benzamidine provides benzimidazole derivatives in moderate to high yields. Remarkably, the procedure occurs exclusively in water and doesn’t require the use of any additional reagent/catalyst, rendering the methodology highly valuable from both environmental and economical points of view.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amination
  • Benzimidazoles / chemical synthesis*
  • Carbonates / chemistry
  • Cyclization
  • Green Chemistry Technology*
  • Iodides / chemistry*
  • Potassium / chemistry
  • Solutions
  • Solvents / chemistry
  • Transition Elements / chemistry*
  • Water / chemistry

Substances

  • Benzimidazoles
  • Carbonates
  • Iodides
  • Solutions
  • Solvents
  • Transition Elements
  • Water
  • potassium carbonate
  • Potassium