RESUMEN
In order to find new cephalosporin with more and more potent antibacterial activity, nine new fourth-generation cephalosporins (N1-N9) were synthesized from ethyl 2-(2-aminothiazol-4-yl)-(Z)-2-methoxyiminoacetate (1) via acylation, substitution, hydrolysis, active esterification, condensation and salt formation. The structures of compounds (N1-N9) were confirmed by IR, MS, 1H NMR and elemental analysis. The target compounds possess different antimicrobial activities against Gram-positive and Gram-negative bacteria. The preliminary results of antibacterial activities revealed that they showed better antibacterial activities against Gram-positive bacteria than cefpirome sulfate. In particular, their activities against Staphylococcus aureus and Streptococcus albus are better.