| abstract |
A process for the preparation of 1,4-bis(4-hydroxybenzoyl)benzene of the formula (I) ##STR1## by rearranging diphenyl terephthalate of the formula (II) ##STR2## in about 3 to about 50 parts, relative to the diphenyl terephthalate, of an anhydrous organic solvent which is inert to the reactants, in the presence of about 30 to about 500 mol-% of a haloalkanesulfonic acid (catalyst) of the general formula (III) or (IV) n n Y(C.sub.n X.sub.2n)SO.sub.3 H (III) n n n Y(C.sub.n F.sub.2n)SO.sub.3 H (IV) n n in which Y is a fluorine or hydrogen atom, and X is a fluorine and/or chlorine atom, with the proviso that at least one X is a fluorine atom, and n is an integer from 1 to 10, at temperatures of about 10° to about 200° C. |