Used as an intermediate in the synthesis of pharmaceuticals, particularly in the development of kinase inhibitors for cancer treatment. It serves as a building block in the preparation of bioactive molecules due to its ability to engage in substitution reactions at the 4-chloro position. Commonly employed in medicinal chemistry for structure-activity relationship studies in quinazoline-based drug candidates. Also utilized in the production of agrochemicals and dyes where heterocyclic frameworks enhance stability and reactivity.