摘要 |
The invention relates to a process for preparing 4-chlorobenzenesulfonic acid from 2-chlorobenzenesulfonic acid and/or 3-chlorobenzenesulfonic acid, comprising the conversion of 2-chlorobenzenesulfonic acid and/or 3-chlorobenzenesulfonic acid to 4-chlorobenzenesulfonic acid in the presence of sulfuric acid at a temperature of 100 to 300° C. The present invention further relates to a process for preparing 4,4′-dichlorodiphenyl sulfone, comprising said process for preparing 4-chlorobenzenesulfonic acid. |