Levofloxacin acid ester

levofloxacin impurity 5 ; levofloxacincyclizedester ; levofloxacin carboxylic acid, ethyl ester ; 7h-pyrido[1,2,3-de]-1,4-benzoxazine-6-carboxylic acid ; 9,10-difluoro-3-(s)-methyl-7-oxo-2,3-dihydro-7h-pyrido[1,2,3-de]-1,4-benzoxazine-6-carboxylate ; levofloxacin cyclization ester ; (s)-ethyl 9,10-difluoro-3-methyl-7-oxo-3,7-dihydro-2h-[1,4]oxazino[2,3,4-ij]quinoline-6-carboxylate ; (s)-ethyl 9,10-difluoro-3-methyl-7-oxo-3,7-dihydro-2h-[1,4]oxazino[2,3,4-ij]quinoline-6-carboxyla ; ethyl (s)-9,10-difluoro-3-methyl-7-oxo-2,3-dihydro-7h-pyrido[1,2,3-de]-1,4-benzoxazine-6-carboxylate ; ethyl (s)-9,10-difluoro-3-methyl-7-oxo-2,3-dihydro-7h-pyrido