N-Dealkyl propafenone Oxalate Salt

N-Dealkyl propafenone oxalate salt is a metabolite-derived impurity arising from the N-dealkylation of propafenone's tertiary amine moiety, retaining the benzofuran-2-ylpropanol core structure. The transformation replaces the propylamino group with a primary amine, which forms a zwitterionic complex with oxalic acid via protonation. This impurity exhibits distinct chromatographic behavior due to altered hydrophobicity and ionization state compared to the parent drug. It serves as a critical HPLC reference standard for quantifying dealkylation pathway impurities in propafenone formulations.