Separation Science and Technology, Vol.42, No.1, 125-135, 2007
Sulfonation of triphenylphosphines and separation of sulfonated triphenylphosphines by crystallization and solvent extraction
The effect of sulfonation conditions on the formation of sulfonated triphenylphosphines and their separation from the post-reaction mixture, containing concentrated sulphuric acid, was studied. The solvent extraction was found to be a suitable technique to separate sulfonated triphenylphosphines from concentrated sulphuric acid, and the purity and yield was higher than obtained by crystallization from various solvents. Tributyl phosphate was a suitable extractant. Sodium salts of sulfonated triphenylphosphines could then be recovered as precipitates by treating the organic phase with the sodium hydroxide solution and separation by crystallization. The solvent extraction simplified the separation process. The separation process was much faster, less chemicals were required, and lower amounts of wastes were produced.