Boc Velpatasvir Keto Impurity

Boc Velpatasvir Keto Impurity is a structurally related API impurity derived from velpatasvir, featuring a tert-butyloxycarbonyl (Boc) protecting group and a keto functionality at the pyrazine ring position. This impurity arises via oxidative degradation of a hydroxyl group in the parent molecule, introducing a carbonyl moiety that disrupts hydrogen bonding interactions. The compound retains the thiophene-fused isoquinoline core and dimethylcarbamoyl side chain characteristic of velpatasvir. Its distinct UV absorption and chromatographic profile enable differentiation from the parent drug. This impurity serves as an HPLC reference standard for quantifying keto-based degradation pathways in velpatasvir formulations.