29 / 2023-07-29 13:34:04

Utilization of Ph3P(O): Restoration of Triphenylphosphine by the “Sulfur Method” Generating Two Valuables

triphenylphosphine oxide,triphenylphosphine sulfide

New Technologies in Phosphorus Chemistry > 1) New reagents and methods in organophosphorus Chemistry

Triphenylphosphine oxide Ph₃P(O) and triphenylphosphine sulfide Ph₃PS, are two byproducts from the industry during the preparation of vitamins and antibiotic drugs.

Since the limited practical applications of these byproducts, currently a lot of them are incinerated as chemical wastes. However, as readily be predicted, a lot of problems associated with this incineration process.

Herein, we report a solution to the problem for treating Ph₃PS (and also a solution to Ph₃PO). As described in Scheme 1, by simply heating a mixture of Ph₃PS and metallic sodium in toluene, in a couple of hours, we can quantitatively convert Ph₃PS to Ph₃P. More importantly, this reaction also generates an equimolar amount of anhydrous Na₂S. Anhydrous Na2S is a very useful chemical that is rather difficult to prepare safely by other methods, although its hydrates Na₂SxH₂O is a quite common chemical. Therefore, this process, the restoration of the chemical waste Ph₃PS to Ph₃P, can produce two chemicals both are highly valuable. The two products Na₂S and Ph₃P can be easily separated by simple filtration, and the solvent toluene can be easily recovered and reused for another reaction. Therefore, this is a reaction that leads to the production of two valuable chemicals with zero-emission from a waste.