A cephem derivative represented by the following formula: ##STR1## wherein R.sub.1 means a fluorine-substituted lower alkyl and A.sub.1 denotes a cyclic or acyclic ammonio group, or a non-toxic salt thereof, is prepared by reacting a compound represented by the following formula: ##STR2## wherein A.sub.1 has the same meaning as defined above, with another compound represented by the following formula: ##STR3## wherein R.sub.1 has the same meaning as defined above, and if necessary, removing the protecting groups.
                            以下是该文本的中文翻译:
由以下公式表示的
头孢菌素衍
生物:##STR1##
其中R.sub.1表示
氟代的低碳基,A.sub.1表示环状或非环状
铵基或其无毒盐,通过将以下公式表示的化合物与另一化合物反应制备而成:##STR2##
其中A.sub.1具有上述定义的相同含义,另一个化合物由以下公式表示:##STR3##
其中R.sub.1具有上述定义的相同含义,如果需要,去除保护基。