| 摘要 |
Cephalosporin esters (I; R = acetyl, 2-phenoxyacetyl, 2-phenylacetyl, N-t-BOC-phenylglycl, 2-(2-thienyl) acetyl, R1 = H, acetoxy, methylthio, etc. R2 = methyl, ethyl, isopropyl, x = chloro, bromo) were prepd. by reacting a cephalosporin acid with a halomethyl ester of a lower alkanoic acid in DMF at less than 50≦̸C and adding an amine at a rate such that the generation of acid anion is equiv. to the rat of esterification.
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