NEW CEPHEM COMPOUNDS AND PROCESSES FOR PREPARATION THEREOF

摘要

Cephem compounds of the formula:

wherein
R<1> is amino a substituted amino group;
R<2> is carboxy or a protected carboxy group;
R<3> is a tetrazolyl group having a lower alkynyl group; and
X is -S- or @

and pharmaceutically acceptable salts thereof, and process for their preparation, and also a pharmaceutical composition comprising, as an effective ingredient, the above compound in association with a pharmaceutically acceptable, substantially nontoxic carrier or excipient. The invention also relates to the starting compounds
R<6a>-S-R<3>
and their preparation.