Used as a key intermediate in the synthesis of quinazoline-based pharmaceuticals, particularly in the development of tyrosine kinase inhibitors for cancer treatment. It serves as a building block in the preparation of active pharmaceutical ingredients (APIs) targeting epidermal growth factor receptor (EGFR) inhibitors. Its structure allows for selective substitution at the amino and chloro positions, enabling the formation of diverse derivatives with potential antitumor, antiviral, and anti-inflammatory activities. Commonly employed in medicinal chemistry research for structure-activity relationship (SAR) studies.