PURPOSE: To obtain the dimer of the title compounds in high selectivity and yield, even in the presence of sulfate ion at a high concentration necessary for the regeneration of disulfate, by reacting a mixture of ethylbenzene and xylene in the presence of an aqueous solution of a peroxodisulfate at a specific temperature.
CONSTITUTION: A diarylalkane compound can be produced by the side-chain dehydrogenative dimerization reaction of a mixture of ethylbenzene and xylene in the presence of an aqueous solution of a peroxodisulfate at ≥100°C, preferably 120W200°C, especially 150W180°C. The molar ratio of the mixture of ethylbenzene and xylene to the peroxodisulfate is ≥2 to 1, preferably 2.5W4.5 to 1. It is necessary to keep the SO2-4 concentration at a high level to attain high current efficiency in the regeneration of peroxodisulfate ion by electrolytic oxidization and, accordinly, the sulfate ion concentration in the aqueous solution at the end of the dimerization reaction is preferably 2W4mol/l, especially 2.5W3.5mol/l.
TERAUCHI TAKASHI
HOSHI SHOICHI
