Carbamic acid, N-[(1S)-1-[[(1R,3S,4S)-3-[6-[7-[2-(6S)-5-azaspiro[2.4]hept-6-yl-1H-imidazol-5-yl]-9,9-difluoro-9H-fluoren-2-yl]-1H-benzimidazol-2-yl]-2-azabicyclo[2.2.1]hept-2-yl]carbonyl]-2-methylpropyl]-, methyl ester

N-[(1S)-1-[[(1R,3S,4S)-3-[6-[7-[2-(6S)-5-Azaspiro[2.4]hept-6-yl-1H-imidazol-5-yl]-9,9-difluoro-9H-fluoren-2-yl]-1H-benzimidazol-2-yl]-2-azabicyclo[2.2.1]hept-2-yl]carbonyl]-2-methylpropyl]-, methyl ester carbamic acid is an impurity of Ledipasvir (L320100), which is most commonly used in combination with sofosbuvir for treatment in chronic hepatitis C genotype 1 patients. It inhibits an important viral phosphoprotein, NS5A, which is involved in viral replication, assembly, and secretion.