4-(Phenylthio)butanoic acid is primarily used in organic synthesis as an intermediate for the production of various pharmaceuticals and agrochemicals. Its unique structure allows it to act as a building block in the synthesis of more complex molecules, particularly those requiring the incorporation of sulfur-containing groups. In pharmaceutical research, it is utilized in the development of compounds with potential therapeutic properties, such as anti-inflammatory or antimicrobial agents. Additionally, it finds application in the preparation of fine chemicals and specialty materials, where its reactivity and functional groups enable the creation of tailored products for specific industrial needs.