CEPHALOSPORIN DERIVATIVES, THEIR PREPARATION AND PHARMACEUTICAL COMPOSITIONS CONTAINING THEM

摘要

New cephalosporin derivatives, of the formula: (I) in which R1 is a heterocyclic, phenyl, p-hydroxyphenyl, phenoxy or dichlorophenylthio radical and R2 is a hydrogen atom, or R1 is phenyl or p-hydroxyphenyl and R2 is an amino radical, R3 is hydrogen, phenyl, substituted phenyl, alkylthio or substituted amino or a radical of the structure -A-R'3, which A is -CH2-, -NH- or -NHCO- and R'3 is a substituted pyridinio radical, R is a carboxyl radical or a carboxylato radical if R3 is a -AR'3 radical and X is a sulphur or oxygen atom, the said alkyl moieties or radicals containing 1 to 4 carbon atoms each in their D, L and D,L forms, where these exist, and their salts are narrow-spectrum anti-bacterial agents which are active against gram-positive bacteria.