Used as a key intermediate in the synthesis of biologically active compounds, particularly in pharmaceutical research. It plays a significant role in the development of kinase inhibitors and antiviral agents. Its structure allows for selective modifications, making it valuable in creating libraries of compounds for drug discovery. Also employed in the preparation of indirubin derivatives, which show potential in cancer therapy due to their ability to inhibit cyclin-dependent kinases. Commonly utilized in organic synthesis for building complex heterocyclic systems.