C₆H₅COCH_{3Colorless crystals with a melting point of 19.6°C and a specific gravity of 1.028; used as a chemical intermediate.}

The method comprises the step of catalytically cracking 1,1-bis(p-isobutylphenyl)ethane at temperatures in the range of 200.degree. to 650.degree. C. in the presence of a protonic acid catalyst and/or a solid acid catalyst to produce p-isobutylstyrene and isobutylbenzene, and at least a portion of said isobutylbenzene is recycled to produce said 1,1-bis(p-isobutylphenyl)ethane by reaction with acetaldehyde in the presence of sulfuric acid.