Daclatasvir Phosphate SRRS impurity

Daclatasvir Phosphate SRRS impurity is a stereoisomeric byproduct arising from the phosphorylation of a secondary hydroxyl group in the daclatasvir core, featuring a 7-(2-aminosulfonylaminopyrimidin-5-yl)-1,3-benzodioxole scaffold with a phosphate ester moiety at the 4-position of the dibenzofuran ring. The SRRS configuration at the chiral centers distinguishes it from the parent drug, introducing a phosphodiester linkage that disrupts NS5A inhibitor activity. This compound serves as a critical HPLC reference standard for quantifying process-related impurities in daclatasvir API synthesis.