Used in research and development as a deuterated analog of sorafenib, a kinase inhibitor. It serves as an internal standard in mass spectrometry-based assays to ensure accurate quantification of sorafenib in biological samples. This aids in pharmacokinetic studies, drug metabolism research, and therapeutic drug monitoring. Its application is crucial for improving the precision and reliability of analytical methods in clinical and pharmaceutical studies, particularly for sorafenib's use in treating liver and kidney cancers.