Used as an intermediate in the synthesis of hair dyes and textile dyes, particularly azo dyes, due to its ability to form colored compounds through diazotization and coupling reactions. It is also employed in the production of certain pharmaceuticals and photographic chemicals. Its sodium salt form improves solubility in aqueous systems, making it suitable for industrial processes requiring water-based reactions. Additionally, it finds use in analytical chemistry as a reagent for detecting specific metal ions.