New, Highly Efficient Work-Up Protocol for Sulfonated Diphosphines

Isolation of a series of sulfonated diphosphines via a new highly efficient method is described. The work-up procedure involves the precipitation of the sulfonated ligand prior to neutralization, and subsequent removal of the sulfuric acid by filtration and washing. Great advantages of this procedure are its simplicity and easiness to scale-up while co-production of large amounts of sulfate salts is avoided.