| 摘要 |
<p>1289392 3 - Hydroxy - 3 - methyl - 7 - aminocepham - 4 - carboxyl derivatives ; cephalo- Sporins ELI LILLY & CO 4 Dec 1970 [24 Feb 1970 (2)] 57731/70 Heading C2A Novel 3 - hydroxy - 3 - methyl - 7 - aminocepham - 4 - carboxyl compounds of general formula wherein R is H, H 2 #, or an amino-protecting group and R<SP>1</SP> is H, an ester group, a salt-forming cation or an anionic charge when R is H 2 #, are prepared by heating a penicillin sulphoxide acid or ester in the presence of sulphuric acid, sulphamic acid, or a soluble salt or ester thereof to about 80‹ C. to about 150‹ C. in a reaction mixture containing at least about 10% by volume of a tertiary carboxamide to yield the acid or ester product, which may then be converted to the desired salts or zwitterions. Known #<SP>3</SP>-cephem-cephalosporins can be prepared from the novel compounds, e.g. 3-methyl- 7 - (2<SP>1</SP> - phenoxy - acetamido) - 3 - cephem - 4- carboxylate is prepared by treating 4<SP>11</SP>-nitrobenzyl 3 - hydroxy - 3 - methyl - 7 - (2<SP>1</SP>- phenoxy - acetamido) - cepham - 4 - carboxylate with acetic anhydride and N,N-dimethylacetamide to yield 4<SP>11</SP>-nitrobenzyl-3-methyl-7-(2<SP>1</SP>- phenoxy - acetamido) - 3 - cephem - 4 - carboxylate and removing the ester group by known hydrogenation methods.</p> |
