Process for the preparation of sulfonated arylphosphines
AssigneeHoechst Aktiengesellschaft
InventorsGuido Albanese, Rainer Manetsberger, Wolfgang A. Herrmann, Christine Schwer
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Abstract
The sulfonation of arylphosphines, which contain at least one aromatic radical which can be sulfonated, is carried out with an anhydrous mixture of sulfuric acid and orthoboric acid. By choosing the appropriate reaction temperature, the process allows selective introduction of the desired number of sulfonic acid radicals into the phosphine molecule and avoids the formation of phosphine oxides. When separating the sulfonation mixture, the orthoboric acid can be separated off together with the sulfuric acid.
Claims20
A process for the preparation of a sulfonated arylphosphine comprising sulfonation of a compound selected from the group consisting of monophosphines, diphosphines, oligophosphines and polyphosphines, said compound containing at least one aryl group, in the presence of an anhydrous mixture of sulfuric acid and orthoboric acid formed by reacting the sulfuric acid and orthoboric acid in the presence of oleum to remove the water of reaction followed by removal of excess SO.sub.3 at a sulfonation temperature of 20.degree. to 350.degree. C. to form a reaction product wherein at least 6.8 moles of orthoboric acid are present per mole of phosphine (III).
Dependencies are inferred from the claim text.