Synthesis and characterization of new quaternary ammonium surfactant [C18-Dabco][Br] and its catalytic application in the synthesis of spirocarbocycles under ultrasonic condition

A novel DABCO-based cationic surfactant [C-18-Dabco][Br] has been easily synthesized by the reaction of DABCO and octadecyl bromide in acetonitrile at room temperature in excellent yield. The synthesizedsurfactant was fully characterized by various techniques like FT-IR, H-1 NMR, C-13 NMR, LC-MS and TGA-DTAanalysis. Furthermore, the critical micelle concentration of the surfactant was determined by the conductivity measurement method. The activity of the [C-18-Dabco][Br] has been demonstrated for the one-pot synthesis of spirocarbocycles under ultrasonic conditions in water. The presence of the long alkyl chain acts as the hydrophobic part while the free tertiary nitrogen site in the surfactant acts as a base and enhances the overall catalytic activity.