1992 Volume 45 Issue 5 Pages 721-734
As a part of our studies on cephalosporins bearing condensed-heterocyclic azolium methyl groups at the 3 position in the cephalosporin nucleus, we describe here the synthesis and antibacterial activity of 7β-[2-(2-aminothiazol-4-yl)-2(Z)-methoxyiminoacetamido] cephalosporins (1-16), 7β-[2-(2-amino-5-chlorothiazol-4-yl)-2(Z)-methoxyiminoacetamido] cephalosporins (17, 18) and 7β-[2-(5-amino-1, 2, 4-thiadiazol-3-yl)-2(Z)-methoxyiminoacetamido] cephalosporins (19-23) containing a variety of condensed-heterocyclic triazolium methyl groups at the 3 position in the cephalosporin nucleus. These cephalosporins exhibited potent antibacterial activity, and it appears that condensed-heterocyclic triazolium as well as condensed-heterocyclic imidazolium rings are effective moieties for improving antibacterial activity and the spectrum of activity. Among the cephalosporins tested, 7β-[2-(2-aminothiazol-4-yl)-2(Z)-methoxyiminoacetamido]-3-(5-methyl[1, 2, 3]triazolo[1, 5-α]pyridinium-1-yl)methyl-3-cephem-4-carboxylate (9) and 7β-[2-(2-aminothiazol-4-yl)-2(Z)-methoxyiminoacetamido]-3-(6-methoxy[1, 2, 4]triazolo[1, 5-α]pyridinium-1-yl)methyl-3-cephem-4-carboxylate (11) showed good antibacterial activity.
