Process for the purification of sulfonated aryl phosphines

Abstract

A process for the purification of salts of at least one member of the group consisting of diphenylphosphine-phenyl-m-sulfonic acid, phenylphosphine-di-(m-phenylsulfonic acid) and triphenylphosphine-tri-(m-sulfonic acid) from aqueous solutions thereof comprising adding at least a molar equivalent amount of at least one member of the group consisting of di-(n-pentyl)-amine, di-(n-hexyl)-amine and water-soluble salts of said amines to an aqueous solution containing at least one member of the group consisting diphenylphosphine-phenyl-m-sulfonic acid, phenylphosphine-di-(m-phenylsulfonic acid), triphenylphosphine-tri(m-sulfonic acid) and salts thereof to adjust the pH value to .ltoreq.7, recovering the precipitate, washing the precipitate and dissolving the same in an aqueous basic solution.

Dependencies are inferred from the claim text.