Oleum sulphonation process.

摘要

A process is provided for obtaining sulphophenyl quaternary ammonium or phosphonium substituted carbonic acid esters. The important step in this process involves reacting a phenyl quaternary ammonium or phosphonium substituted carbonic ester with oleum that contains from 0.5 up to 33% sulphur trioxide. Amounts in excess of 33% sulphur trioxide lead to increased reaction times and, eventually, unacceptable product conversions.