Synthesis of 1-phenyl-1-xylyl ethane by Friedel-Crafts alkylation of xylene with α-methylbenzyl alcohol over mordenite

In the Friedel-Crafts alkylation of xylene to prepare 1-phenyl-1-xylyl ethane (PXE), alpha-methylbenzyl alcohol was used as an alkylating agent over a mordenite catalyst. The catalyst was characterized by MAS-NMR, N-2 adsorption/desorption, NH3-TPD, and various other techniques and was found to possess strong Bronsted acid sites. When temperature was low, the main product was bis-(alpha-methylbenzyl) ether. However, as the temperature went up, PXE and heavies, styrene trimers and heavier oligomers, became main products. The formation of PXE, occurring on strong acid sites, is favored by raising temperature, space velocity, pressure, and xylene/MBA ratio within the experimental ranges. As the catalyst deactivates, the selectivities to PXE and heavies decrease and those to linear dimer and styrene increase. A reaction mechanism is proposed.