| abstract |
A process for the preparation of acyloxybenzenesulfonic acids and salts thereof, of the formula ##STR1## in which R is C 1 -C 17 -alkyl or C 2 -C 17 -alkenyl and M is an alkali or alkaline earth metal, ammonium or hydrogen, including the stages of (a) sulfonation of phenol, if appropriate (b) thermal treatment of the sulfonated phenol, (c) esterification of the sulfonated phenol and if appropriate (d) neutralization of the ester, wherein the sulfonation of the phenol is carried out with sulfuric acid or oleum and the water of reaction is removed during or after stage (b) by distillation and/or by reaction with a dehydrating agent. |