Practical and Simple Synthesis of Substituted Quinolines by an HCl−DMSO System on a Large Scale: Remarkable Effect of the Chloride Ion

A variety of substituted quinolines are synthesized from
imines and enolizable carbonyl compounds under aerobic
conditions, in which only water is a byproduct. In DMSO,
a catalytic amount of HCl activates carbonyl compounds
quite effectively to give the quinolines. A simple and
practical procedure is demonstrated on a large scale.