Friedländer Condensation

Abstract

The preparation of nitrogen‐containing heterocycle (mostly, 2,3‐disubstituted quinolines) from an aromatic ortho ‐aminoaldehyde (or ketone) and an aldehyde (or ketone) bearing an active α‐methylene functionality is regarded to be one of the most successful methods for preparing quinoline derivatives, often in high yield. Therefore, it is generally referred to as the Friedländer condensation, Friedländer synthesis, or Friedländer reaction. The importance of this reaction has been evidenced in the preparation of quinolines, naphthyridines, huprines, and other polycyclic heterocycle derivatives.