Used as a key intermediate in the synthesis of fluorescent dyes and optical brighteners due to its rigid aromatic structure and ability to emit light under UV radiation. Commonly employed in the development of sensors for metal ions and biomolecules, leveraging its fluorescence properties that change upon binding. Also utilized in the preparation of organic semiconductors and luminescent materials for OLEDs. Its carboxylic acid group allows for easy functionalization, making it valuable in pharmaceutical research for building more complex bioactive molecules.