Novel SO3H‐Functionalized Ionic Liquids — Catalyzed Facile and Efficient Synthesis of Polyhydroquinoline Derivatives via Hantzsch Condensation under Ultrasound Irradiation.

A facile and efficient synthesis of polyhydroquinolines has been developed via four-component condensation reactions of aldehydes, dimedone, ethyl acetoacetate, and ammonium acetate in the presence of Novel SO3H-functionalized ionic liquid catalysts through Hantzsch reaction under ultrasound irradiation without solvent. Simple work-up procedure, environmentally friendly, inexpensive, and non-toxic catalyst, shorter reaction times along with excellent product yields are the significant features of this practical method.