Synthesis and in vitro activity of new cephalosporin derivatives containing a benzoxazolone ring.

New cephalosporin derivatives containing a benzoxazolone ring in the side acylamino chain are synthesized using chlorides of non-substituted and halogen substituted (2-benzoxazolone-3-yl) acetic acids for the acylation of the 7-aminodesacetoxy-cephalosporanic acid and 7-amino-cephalosporanic acid amino group. Some of these new compounds exhibit a biological activity higher than that of cephalexin and cephazolin against clinical strains of Staphylococcus aureus, Staphylococcus epidermidis and Streptococcus group A and B.