Used as a key intermediate in the synthesis of pharmaceutical agents, particularly in the development of kinase inhibitors for cancer treatment. Its structure allows for selective modification, making it valuable in creating compounds that target specific signaling pathways in tumor cells. Commonly employed in research settings to design potent and selective inhibitors of tyrosine kinases, which play critical roles in cell proliferation and survival. Also utilized in the preparation of antiviral agents due to its ability to interfere with viral replication enzymes. Its halogenated quinazoline core provides a stable platform for further functionalization in drug discovery programs.