Synthesis of Substituted Quinolines under Aerobic Conditions

Significance

The synthesis of quinolines by cyclocondensation of imines with aldehydes catalyzed by HCl in DMSO under anhydrous but aerobic conditions is reported. The reactions proceed in modest to good yields and the only major by-product of the reaction is water. In DMSO, the acidity of HCl is weaker and therefore chloride is very weakly solvated and can act as a base to effect enolization of aldehydes. Functional group tolerance in both reactants was not widely tested.