| 摘要 |
PURPOSE: A process for preparing cephalosporin is provided, thereby easily preparing cephalosporin in higher purity and yield. CONSTITUTION: A process for preparing cephalosporin comprises the steps of: reacting acid anhydride of 3,5-dichloro-4-pyridinol-1-acetic acid with 7-amino-3-(5-methyl-1,3,4-thiadiazol-2-yl) thiomethyl-3-cephem-4-carboxylic acid in an organic solvent in the presence of base to prepare a cephalosporin compound; adding water into the reaction resulting solution to extract the cephalosporin compound to a water layer; adding an organic solvent into the water layer; and crystallizing the cephalosporin compound to isolate it, wherein the crystallizing organic solvent is selected from the group consisting of ketone, ester, alcohol, ether, amide, nitrile and a mixture thereof; the crystallizing organic solvent is selected from tetrahydrofuran, ethylacetate and a mixture thereof; and the weight amount of the crystallizing organic solvent used is 5 to 20 times of 7-amino-3-(5-methyl-1,3,4-thiadiazol-2-yl) thiomethyl-3-cephem-4-carboxylic acid.
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