Daclatasvir Enantiomer impurity

Daclatasvir Enantiomer Impurity is the non-therapeutic stereoisomer of the antiviral agent daclatasvir, differing in configuration at the chiral center adjacent to the sulfonamide moiety. This impurity retains the core scaffold comprising a tetrahydropyridine ring fused to a benzothiazole, with a substituted phenyl group at the 2-position. The enantiomeric inversion at C-5 introduces distinct diastereotopic interactions, affecting intermolecular recognition and pharmacokinetic properties. Structurally, it maintains the critical hydrogen-bonding pharmacophore but exhibits reversed stereochemistry at the site of metabolic vulnerability. This compound serves as an enantiomeric reference standard for chiral HPLC method validation in API purity assessment.