Restoration of triphenylphosphine using the "sulfur method": two valuable chemicals from waste products.

Ph3P is found to be inert to sodium in toluene even on heating. This phenomenon leads to the finding that in toluene Ph3PS reacts with sodium efficiently and selectively to produce quantitative yields of highly valuable Ph3P and anhydrous Na2S. By applying this finding, anhydrous Na2S can be safely and conveniently prepared using a Ph3P-mediated reaction from sodium and sulfur. This finding also leads to the establishment of a feasible alternative strategy (the sulfur method) for the restoration of the Ph3PO waste to Ph3P that is greener and safer than the currently operating "chlorine method" using phosgene. [ABSTRACT FROM AUTHOR]