Gefitinib impurity 2 is primarily used in the pharmaceutical industry as a reference standard in quality control processes. It plays a critical role in ensuring the purity and safety of gefitinib, a drug used in the treatment of non-small cell lung cancer. By analyzing this impurity, manufacturers can monitor and control the levels of unwanted by-products during the synthesis of gefitinib, ensuring the final product meets regulatory and therapeutic standards. Additionally, it aids in the development of analytical methods for detecting and quantifying impurities in drug formulations, contributing to the overall efficacy and safety of the medication.