WERKWIJZE VOOR DE BEREIDING VAN EEN ANTIBIOTISCH WERKZAME CEFALOSPORINEVERBINDING EN VAN EEN FARMACEUTISCH PREPARAAT MET ANTIBIOTISCHE WERKING.

摘要

Cephem derivatives of the following formula in which the substituents are defined in Claim 1, are prepared by a novel process. In this process, an appropriate 7-acylamidocephem derivative having a protected carboxyl group in the 4-position is reacted in the presence of a molecular sieve with an acylating agent donating the desired acyl radical. The original acyl group is removed from the initially resulting 7-diacylamidocephem derivative. The free acid is obtained by removal of the protective group R'', which preferably represents an easily removable ester group. The said compounds are used as antibiotics.