4-amino-3-mercaptobenzoic acid is primarily used in the synthesis of various pharmaceutical compounds. It serves as a key intermediate in the production of drugs targeting cardiovascular diseases, due to its ability to modulate enzyme activity and improve vascular function. Additionally, it is utilized in the development of chelating agents for heavy metal detoxification, owing to its thiol group, which binds effectively to metal ions. In organic chemistry, it is employed in the preparation of heterocyclic compounds, which are essential in creating dyes, pigments, and other specialty chemicals. Its unique structure also makes it valuable in research for studying biochemical pathways and developing novel therapeutic agents.