Diethylphosphinic chloride is widely used in organic synthesis as a key intermediate for the preparation of various phosphorus-containing compounds. It is particularly valuable in the production of flame retardants, where it enhances the fire resistance of materials such as plastics, textiles, and coatings. Additionally, it serves as a reagent in the synthesis of organophosphorus ligands, which are crucial in catalysis and coordination chemistry. Its reactivity with alcohols and amines makes it a versatile building block for creating specialized chemicals used in agrochemicals and pharmaceuticals.