Studies of 7 beta-[2-(aminoaryl)acetamido]-cephalosporin derivatives. II. Synthesis and structure-activity relationships in the aminopyrimidine series.

The synthesis and the antibacterial activity of 7 beta-[2-(aminopyrimidinyl)-2-oxyiminoacetamido]cephalosporin s with various substituents at the 3-position in the cephem nucleus are described. The 7 beta-[2-(4-aminopyrimidin-2-yl)-2 -methoxyiminoacetamido]cephalosporin derivative (1) showed significantly higher activity than the corresponding 2-aminopyrimidin-4-yl derivative (2) against Gram-negative bacteria. It was also higher in potency against Escherichia coli and Serratia marcescens than the aminopyridyl compound (4).