5,6-Diaminopyrimidine-2,4-diol sulfate is primarily used in the synthesis of pharmaceutical compounds, particularly in the development of antiviral and anticancer drugs. Its structure serves as a key intermediate in the production of nucleoside analogs, which are essential for inhibiting viral replication and targeting cancer cells. Additionally, it is employed in biochemical research for studying enzyme mechanisms and nucleic acid interactions due to its ability to mimic natural nucleobases. The compound also finds application in the preparation of dyes and pigments, where its chemical properties contribute to the stability and color intensity of the final products.