Velpatasvir Impurity 20

Chemical Name: Des (N-(Methoxycarbonyl)-L-Valine) Velpatasvir; methyl ((R)-2-((2S,4S)-4-(methoxymethyl)-2-(5-(2-((2S,5S)-5-methylpyrrolidin-2-yl)-1,11-dihydroisochromeno[4',3':6,7]naphtho[1,2-d]imidazol-9-yl)-1H-imidazol-2-yl)pyrrolidin-1-yl)-2-oxo-1-phenylethyl)carbamate