Isocarbostyril is primarily used in the field of organic synthesis as a key intermediate for the production of various pharmaceuticals. Its structure makes it a valuable building block for the development of compounds with potential therapeutic properties, particularly in the synthesis of alkaloids and other bioactive molecules. It is also explored in the design of fluorescent dyes and pigments due to its ability to form stable, conjugated systems. Additionally, isocarbostyril derivatives are studied for their potential applications in material science, particularly in the development of organic semiconductors and light-emitting materials.