Used primarily as a reagent in analytical chemistry for the detection of hydrogen sulfide and other sulfur compounds. It reacts with these compounds to form a colored product, making it valuable in environmental monitoring and industrial safety applications. Additionally, it serves as an intermediate in the synthesis of dyes and pigments, particularly in the production of hair dyes and textile colorants. Its role in organic synthesis extends to the preparation of various pharmaceuticals and agrochemicals, where it acts as a building block for more complex molecules.