Used as an intermediate in the synthesis of pharmaceuticals, particularly in the development of isoquinoline-based compounds with biological activity. It serves in the preparation of potential antitumor, antimicrobial, and anti-inflammatory agents due to the reactivity of the chlorine atom, which allows for substitution with nucleophiles such as amines or thiols. Also employed in research settings for constructing complex heterocyclic systems in medicinal chemistry and in the design of kinase inhibitors. Its methyl and chloro substituents offer sites for further functionalization, making it valuable in combinatorial chemistry and drug discovery.