CEPHAM COMPOUNDS, PHARMACEUTICAL COMPOSITIONS CONTAINING THEM AND PROCESSES FOR THE PREPARATION THEREOF AND OF KNOWN CEPHEM COMPOUNDS

摘要

Novel compounds of the formula: wherein R<1> is amino or a protected amino group, R<2> is carboxy or a protected carboxy group, R<3> is formyl, hydroxymethyl or acyloxymethylene, and X is -S- or -SO-, e.g. 7-[2-(2-aminothiazol-4-yl)-2-methoxyimino-acetamido]-3-acetoxymethylen ecepham-4-carboxylic acid (syn isomer), salts thereof and processes for their preparation. The invention also relates to pharmaceutical compositions comprising, as effective ingredients, the above coumpounds in association with a pharmaceutically acceptable, substantially nontoxic carrier or excipient, and to a process for their preparation. Also a process for preparing known cephem compounds of the formula starting from some of the above new compounds is described. o