Process to prepare diazinon

摘要

Diazinon is prepared by coverting the starting hydroxypyrimidine to its potassium salt by reacting it with potassium carbonate in an organic solvent after removal of the water by azeotropic distillation, and reacting the resulting non-aqueous salt with diethyl thiophosphoryl chloride and recovering the diazinon formed, wherein the quantity of potassium carbonate used relative to the starting hydroxypyrimidine is less than molar and desirably of a ratio in the range of 0.55 to 0.75.