Rapid synthesis of quinoline-4-carboxylic acid derivatives from arylimines and 2-substituted acrylates or acrylamides under indium(III) chloride and microwave activations. Scope and limitations of the reaction.

Rapid synthesis of quinoline-4-carboxylic acid derivatives has been achieved by reaction of 2-methoxy acrylates or acrylamides with N-arylbenzaldimines in acetonitrile under InCl3 catalysis and microwave irradiation. Isolated yields up to 57% within 3 min have been obtained. The Lewis acid and the microwave activation appeared as crucial parameters for the reaction. The role of indium chloride and ytterbium triflate was specified using 13C NMR data and model theoretical studies.