Process for preparing sulfonated arylphosphines

摘要

A process for preparing sulfonated arylphosphines by reaction of arylphosphines with oleum, wherein, after reaction of the arylphosphines with oleum, the sulfonation mixture is firstly diluted with water, an inert gas stream is then passed through the diluted sulfonation mixture until SO₂ is no longer liberated from the diluted sulfonation mixture and the latter is then worked up further in a customary manner and its use.