Triphase catalytic activity of a new insoluble multi-site phase transfer catalyst in C-alkylation of dihydrocarvone—A kinetic study

A new insoluble multi-site triphase catalyst viz., polymer-supported 1,3,4-tris(triethylammoniummethylene chloride)-2-methylbenzene (PSTTACMB) containing three active sites was synthesized by simplified procedure and its structure was characterized by FT-IR, solid 13C NMR, TGA, [chloride ion] and SEM analyses. The catalytic efficiency of PSTTACMB was ascertained by comparing with insoluble single-site PTC viz., polymer-supported benzyltriethylammonium chloride (PSBTEAC) through determination of pseudo-first order rate constant for C-alkylation of dihydrocarvone with 1-bromobutane using 25% (w/w) NaOH at 60 °C under identical experimental conditions. Further, the dependency of rate of C-alkylation of dihydrocarvone on different kinetic variables was studied by varying the stirring speed, [substrate], [catalyst], [NaOH] and temperature. Based on the observed kinetic results and activation energy, a suitable mechanism was proposed.

Graphical abstractNew insoluble multi-site phase transfer catalyst containing three active sites was synthesized, characterized and catalytic activity was determined through C-alkylation of dihydrocarvone using NaOH (25%, w/w) at 60 °C.Figure optionsDownload full-size imageDownload as PowerPoint slide