| 摘要 |
<p>Cephalosporins of formula (I) comprises reacting 7-amino cpds. of formula (II) wiht acylating agents CNCH2. CO.O.Q (III). (M is H,Na,K, NH4, tri(lower alkyl)amino or trimethylsilyl; Q is CNCH2CO or SO2R; R is CH3, C2H5, C3H7, C6H5, ptolyl, OLi, ONa or OK). Pref. reaction is in an inert solvent at -20 to 0 degrees C. (I) are antibiotics suitable for intramuscular application. (III) react to give (I) only, unlike mixed anhydrides with other carboxylic acids which give mixts. from which it is difficult to separate (I). (III) can be prepared in situ. In an example, Na cephacetril was prepd. by reacting 7-ACA with CNCH2. CO.O.SO2CH3, then adding Na acetate.</p> |
