6-Hydroxyquinoline-3-carboxylic acid is primarily utilized in the field of organic synthesis and pharmaceutical research. It serves as a key intermediate in the production of various biologically active compounds, particularly those with potential therapeutic applications. Its structure allows it to act as a building block for the development of drugs targeting specific enzymes or receptors. Additionally, it is employed in the synthesis of fluorescent dyes and probes, which are useful in biochemical and cellular imaging studies. Its chelating properties also make it relevant in the study of metal ion interactions in biological systems.