1. Field of the Invention
The present invention relates to novel intermediates useful for the production of cephalosporin derivatives which are useful in the pharmaceutical fields, and a process for the production of the intermediates.
2. Discussion of Background
Since .beta.-lactam antibiotics exhibit selective toxicity only against bacteria and present no substantial effects against animal cells, they have performed important roles as antibiotics with no substantial side effects in the prevention or treatment of diseases caused by the infection of bacteria.
Particularly, cephalosporin derivatives are generally stable against penicillinase and have a broad antibacterial spectrum, and thus they are frequently employed for the prevention and treatment of diseases caused by the infection of bacteria.
On the other hand, however, a cephalosporin derivative having a more potent and broader antibacterial spectrum is desired in that few existing cephalosporins are adequately active for the curing of obstinate infectious diseases caused by resistant Staphylococci, or glucose non-fermentative Gram-negative rods such as resistant Pseudomonas aeruginosa, or Acinetobacter calcoaceticus which have various resistant mechanisms.
Under the circumstances, the present inventors have conducted extensive researches on cephalosporin derivatives, and as a result, have found that a group of cephalosporin derivatives having an isoindolinium methyl group substituted by two hydroxyl groups at adjacent positions, introduced at the 3-position of the cephem nucleus, exhibit remarkably strong antibacterial activities against Gram-negative bacteria, particularly against glucose non-fermentative Gram-negative rods such as Pseudomonas aeruginosa, Pseudomonas cepacia and the like (Japanese patent application No. 292183/1985).