ledipasvir interMediate;InterMediate of Ledipasvir;(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;(6S)-tert-butyl-6-(5-(7-broMo-9,9-difluoro-9H-fluoren-2-yl)-1H-iMidazol-2-yl)-5-azaspiro[2Open