Abstract:
The invention provides new fluorinated cephalosporin antibiotics of Formula I wherein R , R , R , R and R , independently, are H, F or a C -C alkyl-(Z) â group having at least one fluorine substituent; X is O or S; Y is S, O, or âCH â; Z is O, S, âSOâ, or âSO â; m and n independently are 0 or 1; and R is H, C -C -alkyl, phenyl or benzyl, each of which may optionally have up to three substituents selected from halo, C -C -alkoxy, phenyl, NO , C -C -alkanoyl, benzoyl, or C -C -alkanoyloxy; or a physiologically acceptable salt thereof; and methods of preventing or treating or treating infection, particularly mastitis in ruminants, using these antibiotics.