Dapagliflozin dimer impurity-1

Dapagliflozin dimer impurity-1 arises from head-to-tail coupling of two dapagliflozin monomers via a glycosidic linkage between the C1-anomeric hydroxyl of one glucosamine moiety and the C6-hydroxyl of the adjacent benzofuran ring. This dimer exhibits a fused biphenyl core with extended conjugation, retaining the characteristic sulfonamide and pyran-2-one pharmacophores of the parent compound. The intermolecular linkage introduces a rigid, planar scaffold that enhances chromatographic resolution during HPLC analysis. This impurity serves as a reference standard for quantifying dimerization byproducts in dapagliflozin synthesis.