Synthesis of 1-phenyl-1-tolyl ethane by Friedel–Crafts alkylation of toluene with α-methylbenzyl alcohol over acidic zeolites Original Research Article

In the Friedel–Crafts alkylation of toluene to prepare 1-phenyl-1-tolyl ethane (PTE), α-methylbenzyl alcohol was used as an alkylating agent instead of styrene over large- and medium-pore zeolites. The catalysts were characterized by 27Al and 29Si MAS-NMR, NH3-TPD, SEM, N2 adsorption/desorption, and other techniques. Among the four zeolites investigated, the acid strength was approximately in the order of HMOR20 > HY5 ≥ HMFI30 > HBEA25 while the initial selectivity to PTE was in the order of HMOR20 > HBEA25 > HMFI30 > HY5. From the reaction and characterization studies, it is concluded that the formation of PTE requires both strong acid sites and suitable pore openings, which prevent heavy oligomers from forming in the channels while facilitating the transport of the reactants and products. HMOR20 showed the best overall performance as it satisfied these requirements.