A convenient and efficient protocol for the synthesis of acylals catalyzed by Brønsted acidic ionic liquids under ultrasonic irradiation

The synthesis of acylals (1,1-diacetates) via the reactions of aldehydes with acetic anhydride was carried out in 85–97% yields at room temperature under ultrasound irradiation catalyzed by the Brønsted acidic ionic liquid [bmpy]HSO4. This method provides several advantages, such as solvent-free conditions, operational simplicity, higher yields, and reduced environmental consequences. The ionic liquid was recovered and reused.

► Synthesis of acylals under ultrasonic irradiation.
► Reaction catalyzed by [bmpy]HSO4 ionic liquid.
► Simple and mild solvent-free reaction conditions.
► Ionic liquid can be easily prepared.