| 摘要 |
<p>Cephem compounds of the general formula I in which R<2> is 2,2-dihalovinyl or ethinyl, and R<3> is carboxyl or protected carboxyl, and the pharmaceutically acceptable salts thereof are obtained by deacylating a compound of the formula II in which R<2> and R<3> have the above meaning, and R<1> is acylamino, or a salt thereof, by reaction with an imino halogenating agent and then with an imino etherifying agent and, if necessary, hydrolysing the resulting compound, and, if necessary, removing the protective group from a resulting compound in which R<3> is protected carboxyl by hydrolysis. They are employed as intermediates for the preparation of other cephem compounds having valuable antimicrobial activity. <IMAGE></p> |
