Used primarily as a reference standard or impurity marker in pharmaceutical analysis, this compound plays a critical role in quality control during the synthesis and purification of nintedanib, a tyrosine kinase inhibitor used in the treatment of idiopathic pulmonary fibrosis and certain cancers. It helps in identifying and quantifying impurities in drug substances and formulations, ensuring compliance with regulatory requirements for purity and safety. Its presence is monitored during stability studies to assess degradation pathways and shelf life of the active pharmaceutical ingredient.