Synonyms: (S)-tert-butyl 6-(5-(7-broMo-9,9-difluoro-9H-fluoren-2-yl)-1H-iMidazol-2-yl)-5-azaspiro[2.4]heptane-5-carboxylate;5-Azaspiro[2.4]heptane-5-carboxylic acid, 6-[5-(7-broMo-9,9-difluoro-9H-fluoren-2-yl)-1H-iMidazol-2-yl]-, 1,1-diMethylethyl ester, (6S)-;(6S)-6-[5-(7-Bromo-9,9-difluoro-9H-fluoren-2-yl)-1H-imidazol-2-yl]-5-azaspiro[2.4]heptane-5-carboxylic acid 1,1-dimethylethyl ester;(6S)-tert-butyl-6-(5-(7-broMo-9,9-difluoro-9H-fluoren-2-yl)-1H-iMidazol-2-yl)-5-azaspiro[2.4]heptane-5-carboxylate;InterMediate of Ledipasvir