DES (N-(Methoxycarbonyl)-L-valine) Velpatasvir

DES (N-(Methoxycarbonyl)-L-valine) Velpatasvir is a structurally related API impurity arising from the methoxycarbonylation of the L-valine moiety in the parent drug's synthetic pathway. It features a substituted amino acid backbone with a methoxycarbonyl (COOCH₃) group at the N-terminus, diverging from Velpatasvir's core scaffold through a specific esterification byproduct. This compound represents a critical process-related impurity, serving as an HPLC reference standard for impurity profiling in Velpatasvir drug substance analysis.