Process for preparing cephalosporin compounds.

摘要

There is described a process for the preparation of compounds of general formula (I) <CHEM> (wherein R<1> is an amino or protected amino group, R<2> is hydrogen or a carboxyl blocking group, B is @S or @S -> O and the dotted line bridging the 2-, 3- and 4- positions indicates that the compound is a ceph-2-em or ceph-3-em compound) or a corresponding compound having a group of formula COOR<3> at the 4- position (wherein R<3> is a carboxyl blocking group) and having an associated anion A<(-)>, and salts thereof, which comprises reacting a compound of general formula (II)