Used primarily as a reference standard or impurity control in the pharmaceutical industry for quality assurance and analytical testing of Dacomitinib, an epidermal growth factor receptor (EGFR) inhibitor used in cancer treatment. It helps in validating analytical methods, monitoring degradation products, and ensuring the purity and stability of the active pharmaceutical ingredient. Its presence is studied to assess process-related impurities during synthesis and to support regulatory filings by characterizing potential by-products.