Canagliflozin dimer impurity-1

Canagliflozin dimer impurity-1 is a dimeric byproduct formed via oxidative coupling of two canagliflozin molecules through their benzyl hydroxyl groups, resulting in an ether linkage between the pyranose rings. This symmetrical dimer retains the core triazole and phthalimide moieties of the parent drug, with extended conjugation across the dimer interface. The compound arises during synthetic oxidation steps or storage degradation under aerobic conditions. It serves as a critical HPLC reference standard for quantifying dimeric impurities in canagliflozin active pharmaceutical ingredient batches.