| abstract |
The compounds correspond to the formula: <IMAGE> in which R1 represents hydrogen or certain protective groups, R2 represents certain alkyl radicals, R3 represents C1-C4 alkyl or alkoxy radicals and A represents hydrogen, an alkali metal, alkaline-earth metal, magnesium or amine cation or an ester group; the preferred compounds have the syn configuration. The preparation is carried out by creating the amide bond from the carboxyl component and the substituted 7-aminocephem component, followed by an acid hydrolysis, a hydrogenolysis or a treatment with thiourea when it is desired to remove the protective groups R1 and A. The compounds are active with respect to gram (+) and (-) bacteri; they can be used in the treatment of relevant infections.n[GB1575180A] |