Diethyl oxalacetate sodium salt is primarily used in organic synthesis as a versatile intermediate. It plays a crucial role in the preparation of various heterocyclic compounds, which are essential in pharmaceutical research and development. This chemical is also employed in the synthesis of fine chemicals and agrochemicals, contributing to the creation of products like herbicides and fungicides. Additionally, it serves as a key reagent in biochemical studies, particularly in enzymatic reactions and metabolic pathway research. Its application extends to the field of material science, where it aids in the development of specialized polymers and coatings.