Design and synthesis of new cephalosporin antibiotics

Cephalosporins are important antibiotics. We synthesized new cephalosporin analogs containing novel side chains of methyl, propyl, benzyl, and phenoxy groups. Four synthetic methods with N-alkylation and N-acylation at position C-7 and esterification at position C-4 of 7-aminodesacetoxycephalosporanic acid are reported here.