A liquid-liquid process for production of 2,4-diphenyl-4-methyl-1-pentene by dimerization of alpha-methylstyrene

A liquid-liquid process for the dimerization of alpha-methylstyrene (AMS) i n order to produce selectively the commercially useful 2,4-diphenyl-4-methy l-1-pentene has been developed, The aqueous phase contained sulfuric acid a s a catalyst and methanol as an additive, and the organic phase was 97% alp ha-methylstyrene (AMS). An AMS conversion of 55% was achieved in 7 h when t he dimerization was conducted at 80 degrees C, The product dimer contained 93% 2,4-diphenyl-4-methyl-1-pentene and only 0.06% 1,1,3-trimethyl-3-phenyl indan, the saturated dimer, The liquid-liquid process can be used commercia lly to produce selectively 2,4-diphenyl-4-methyl-1-pentene at locations whe re cation-exchange resins are not readily available.