Ultrasound assisted dichlorocarbene addition to 1,3-bis(allyloxy)-5-methylbenzene under biphasic condition: A kinetic study

A new multi-site phase-transfer catalyst (MPTC), viz., N,N’-dioctyl-4,4’-bipyridium dibromide containing bi-site was prepared and proved by FT-IR, 1H NMR, 13C NMR, mass and elemental analysis. The enhancement of C-N+ peak intensity at 1179 cm−1 noticed in FT-IR, the agreement of m/z values, viz., 542.43 bi-site respectively with their theoretical values and the percentage of C, H, N elements noticed in elemental analysis has strongly supported the presence of tri-site MPTC catalysts. Further, the presence of number of active-sites in the catalyst was again confirmed by determining their pseudo-first order rate constant for dichlorocarbene addition to 1,3-bis(allyloxy)-5-methylbenzene in the presence of ultrasonic irradiation/mechanical stirring. The comparative study reveals that the kapp determined with the combination of ultrasound and mechanical stirring has shown more activity than with their individual effect. Further, the detailed kinetic study performed with superior di-site MPTC reveals that the kapp are dependent with the stirring speed, [substrate], [catalyst], [NaOH] and temperature. Based on the kinetic results, thermodynamic parameters are evaluated.

Keywords:

Ultrasound irradiation , dichlorocarbene , phase-transfer catalysis , kinetic Study