Swift and efficient synthesis of 4-phenylquinazolines: involvement of N-heterocyclic carbene in the key cyclization step

J Org Chem. 2010 Mar 19;75(6):2092-5. doi: 10.1021/jo902726k.

Abstract

An original route to 2-alkyamino-4-phenylquinazolines in three steps from simple (hetero)aromatic amines is reported here. The key step involves the intramolecular cyclization of benzoyl arylguanidines performed in [OMIm]Cl ionic liquid. The basic (hetero)aromatic guanidines deprotonate the imidazolium-based ionic liquid, thus triggering the cascade process ultimately leading to the intramolecular cyclization. This reaction is the first example of a Friedel-Crafts-type reaction in which an N-heterocyclic carbene is involved in the formation of the electrophilic intermediate.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Cyclization
  • Guanidine / chemical synthesis
  • Guanidine / chemistry
  • Heterocyclic Compounds / chemistry*
  • Methane / analogs & derivatives*
  • Methane / chemistry
  • Molecular Structure
  • Quinazolines / chemical synthesis*
  • Quinazolines / chemistry

Substances

  • Heterocyclic Compounds
  • Quinazolines
  • carbene
  • Guanidine
  • Methane