Used as a key intermediate in the synthesis of fluorescent dyes and optical brightening agents, particularly in textile and paper industries. Its structure supports conjugation systems that enhance light absorption and emission, making it valuable in developing sensors and probes for bioimaging. Also employed in the preparation of pharmaceuticals where the isobenzofuranone core is part of biologically active molecules. Its amine group allows for easy functionalization, enabling coupling reactions in organic synthesis and material science applications.