Ultrasound mediated synthesis of aldimines from non-enolizable aldehydes at room temperature

A user-friendly, energy efficient method of synthesizing N-sulfonyl aldimines at room temperature (25‒28°C) from readily available and inexpensive reagents has been developed. The method employs ultrasonication from common laboratory ultrasonic cleaner to mediate the reaction. FeCl3 as catalyst and molecular sieves as water scavenger have produced excellent yields of aldimines with short reaction time. The reaction set-up does not require inert atmosphere or anhydrous solvent thereby saving resources and time. The easily scalable method works well for the condensation of aromatic non-enolizable aldehydes and sulfonamides