An atom-efficient and practical synthesis of new pyridinium ionic liquids and application in Morita-Baylis-Hillman reaction.

New ionic liquids containing (3-chloro-2-hydroxypropyl)-functionalized pyridinium cations have been synthesized by the ultrasound-assisted, atom-efficient, room temperature reaction of pyridine with acid and 3-chloro-propylene oxide, the acid providing the anionic component of the resultant ionic liquids, and under the ultrasound, a clear yield increase results and a dramatic reduction of the reaction time accompanied by an improved quality of the products occurs. Furthermore, the application of new ionic liquids were tested as solvents in Morita-Baylis-Hillman reaction, in some cases, good results were obtained.