N,N'-Diethylhydrazine dihydrochloride is primarily utilized in organic synthesis as a versatile reagent. It plays a significant role in the preparation of hydrazine derivatives, which are essential intermediates in the production of pharmaceuticals, agrochemicals, and dyes. The compound is particularly valuable in the synthesis of heterocyclic compounds, which are foundational structures in many biologically active molecules. Additionally, it is employed in research laboratories for studying reaction mechanisms and developing new synthetic methodologies. Its application extends to the field of polymer chemistry, where it is used to modify polymers and create specialized materials with unique properties.