| abstract |
ABSTRACT OF THE DISCLOSURE The present invention relates to novel 7-acylamino and 7-amino-3-(substituted)carbonylamino-3(or 2)cephem-4-carboxylic acids and esters thereof, which are useful as antibiotics or as intermediates in preparing antibiotic substances respectively, and to a process for preparing said compounds. In particular, this invention relates to cepha-losporins having in the 3-position a carbonylamino (iso-cyanato) or a substituted carbonylamino group, such as acylamino, ureido or substituted ureido, alkoxycarbonyl-amino, or (alkylthio) carbonylamino. |