(T-4)-Bis(acetato-κO)[1-cyclopropyl-6,7-difluoro-1,4-dihydro-8-methoxy-7-4-(oxo-κO)-3-quinolinecarboxylato-κO3]boron-13C,D3 is an intermediate used in the synthesis of Moxifloxacin Hydrochloride-13CD3 (M745003), which is a fluorinated quinolone antibacterial.