Process for the production of neutral phosphoric acid esters

In the process for the production of neutral phosphoric acid esters comprising reacting a phosphorus halide selected from the group consisting of phosphorus oxyhalides, phosphorus pentahalides, phosphoric acid monoester dihalides and phosphoric acid diester halides with at least one phenolic compound in a two phase mixture of an organic solvent and an aqueous solution of a hydroxide of an alkali metal, alkaline earth metal or mixtures thereof, the improvement comprises using 1.01 to 4 moles of said phenolic compound and 1.01 to 2 moles of said hydroxide for each mole equivalent of phosphorus halide, the organic solvent being present in sufficient amount to form a 10 to 50% by weight solution of the product neutral phosphoric acid ester and upon completion of the reaction separating the organic solvent phase from the aqueous phase and isolating the neutral phosphoric ester by removing the organic solvent.