Tamoxifen Dimer (Mix of diastereomers)

Tamoxifen Dimer (Mix of diastereomers) is a dimeric byproduct formed via coupling of two Tamoxifen molecules through their central ethylene moieties, generating a biphenyl-linked structure with pendant triphenylethylene units. The diastereomeric configuration arises from stereochemical variability at the coupling site, resulting in distinct spatial arrangements of hydroxyl and dimethylamino substituents. This impurity exhibits a methylene bridge between the terminal aromatic rings, creating a rigid, conjugated framework. It functions as a reference standard for HPLC-based quantification of dimeric impurities in Tamoxifen drug substance synthesis.