New aminothiazolylglycylcephalosporins with a 1,5-dihydroxy-4-pyridone-2-carbonyl group. I. Synthesis and biological activity of cephalosporin derivatives leading to MT0703.

A series of new aminothiazolylglycylcephalosporins with a mono- or dihydroxypyridonecarbonyl group at the alpha-amino group of the C-7 substituent have been prepared and antibacterial activity of these compounds was investigated. Among them, the compounds having a 1,5-dihydroxy-4-pyridone-2-carbonyl group showed excellent anti-pseudomonal activity. In particular, (6R,7R)-7-[(RS)-2-(2-aminothiazol-4-yl)-2-(1,5-dihydroxy-4- pyridone-2-carboxamido)- acetamido]-3-[[1-(2-hydroxyethyl)pyridinium-4-yl]thiomethyl]ceph-3 -em- 4-carboxylate (MT0703, 7g) was found to be a well balanced compound with respect to antibacterial activity.