2',2'-Difluoro-2'-deoxycytidine-3',5'-dibenzoate (Gemcitabine impurity);Gemcitabine impurity 4/2',2'-Difluoro-2'-deoxycytidine-3',5'-dibenzoate;2'-deoxy-2,2'-difluoro-3,5-dibenzyl-cytidine;2',2'-Difluoro-2'-deoxycyodine-3',5'–dibenzoate ( or its salt) 2'-deoxy-2',2'-difluoro-3',5'-di-O-benzoates-cytidine (or its salt);Cytidine, 2'-deoxy-2',2'-difluoro-, 3',5'-dibenzoate (9CI);2’-Deoxy-2’,2’-difluoro-3’,5’-bis-O-benzoylcytidine;2’-Deoxy-3’,5’-di-O-benzoyl-2’,2’-difluorocytidine;Chloropurine riboside