4-(4-Amino-3-fluorophenoxy)-N-methylpyridine-2- carboxamide

4-(4-Amino-3-fluorophenoxy)-N-methylpyridine-2-carboxamide is a structurally defined impurity of the kinase inhibitor Regorafenib, featuring a substituted phenoxy moiety linked to a N-methylcarboxamide-functionalized pyridine ring. The 4-amino and 3-fluoro substituents on the phenoxy aromatic system confer distinct electronic and steric properties, while the methylated amide enhances metabolic stability. This compound arises as a synthetic byproduct during Regorafenib production via nucleophilic aromatic substitution pathways. It serves as an HPLC reference standard for quantifying process-related impurities in bulk drug substance analysis.