Propargylation of indene-1,3-dione under a new phase-transfer catalyst combined with ultrasonication – A kinetic study

•A new phase-transfer catalyst was used for propargylation of indene-1,3-dione.•Effect of ultrasound was studied in this reaction.•Different frequency of ultrasound irradiation was tested.•A suitable reaction mechanism was proposed for this reaction.

In the present study, kinetics of synthesis of 2,2-di(prop-2-ynyl)-1H-indene-1,3(2H)-dione was successfully carried out by propargylation of indene-1,3-dione with propargyl bromide using aqueous potassium hydroxide and catalyzed by a newly synthesized phase-transfer catalyst viz., N-benzyl-N-ethyl-N-isopropylpropan-2-ammonium bromide, PTC under ultrasonic (40 kHz, 300 W) assisted organic solvent condition. The pseudo first-order kinetic equation was applied to describe the overall reaction. Under ultrasound irradiation (40 kHz, 300 W) in a batch reactor, it shows that the overall reaction rate can be greatly enhanced with ultrasound irradiation than without ultrasound.