Cephalosporin derivatives, their preparation and compositions containing them

摘要

Cephalosporin derivatives of the formula: <IMAGE> (I) in which A is a single bond or a radical -CH2-, -NH- or -NHCO-, attached to the 3-position or 4-position of the pyridinio radical, R is a methyl, carboxymethyl, carbamoylmethyl, benzyl or allyl radical, Ra, Rb and Rc are hydrogen atoms, or alternatively Ra is carboxyl and Rb and Rc, which are identical or different, are hydrogen atoms or alkyl radicals, or together form an alkylene radical, and n equals 0 or 1, in their syn form, and also their addition salts with acids, metal salts and addition salts with nitrogen-containing bases are antibacterial agents having a broad spectrum of activity.