A facile one-pot ultrasound assisted synthesis of 1,8-dioxo-octahydroxanthene derivatives catalyzed by Brّnsted acidic ionic liquid (BAIL) under green conditions

A simple and efficient one-pot procedure for the synthesis of 1,8-dioxo-octahydroxanthene derivatives in water under ultrasound irradiation is described. These heterocycles were prepared by condensation of dimedone with various aromatic aldehydes in the presence of Brّnsted acidic ionic liquids as a convenient, cheap, readily synthesized and eco-friendly catalyst. This procedure has a lot of advantages such as: excellent yields, simplicity of the workup, low cost, short reaction times and green conditions. Ionic liquids could be recycled several times without significant loss of activity and high purity.