Levofloxacin Q-Acid

; Levofloxacin Q Acid ;|(Levofloxacin Difluoro Impurity);|Levofloxacin Related Compound B.|Levofloxacin USP RC B ; Levofloxacin Difluoro Carboxylic Acid ; (S)-9,10-Difluro-3-methyl-7-oxo-2,3-dihydro-7H-pyrido[1,2,3-de][1,4]benzoxazine-6-carboxylic acid ;