Used primarily as a reference standard or impurity control in the pharmaceutical industry during the synthesis and quality testing of dacomitinib, a tyrosine kinase inhibitor used in cancer treatment. Helps ensure the purity, safety, and consistency of the active pharmaceutical ingredient by identifying and quantifying trace impurities in drug formulations. Also utilized in analytical studies to develop and validate sensitive detection methods such as HPLC and mass spectrometry. Its presence and behavior under various conditions support stability testing and process optimization in drug manufacturing.