Traditional process
Phosphorus trihalides are gradually added to a container holding phenyl magnesium halides. This method has a low overall yield, with a product content of less than 90%, and produces a large amount of byproducts.
Improved process
A small amount of cyclic organic solvent (such as tetrahydrofuran, tetrahydropyridine, etc.) is added to the reaction vessel beforehand.
Phenyl magnesium halides and phosphorus trihalides are added simultaneously and continuously, maintaining the reaction mixture temperature between room temperature and the boiling point of the mixture.
After the reaction is complete, an acid electrolyte is added for hydrolysis, the magnesium halide is separated, solvent is removed under reduced pressure, and recrystallization yields a high-purity product.
The improved process achieves a yield of up to 90%, with a significant reduction in byproducts.
