Pyrazine-2,5-diamine dihydrochloride is primarily used in the synthesis of various pharmaceutical compounds. It serves as a key intermediate in the production of drugs that target bacterial infections, making it valuable in the development of antibiotics. Additionally, it is utilized in the creation of dyes and pigments, particularly in industries requiring high-precision colorants. Its role in organic synthesis extends to the preparation of complex molecules for research and industrial applications, contributing to advancements in medicinal chemistry and material science.