Process for purifying cephalosporin compounds

Abstract

A cephalosporin compound of the formula: ##STR1## wherein X is hydrogen, halogen, hydroxy, alkyloxy, aralkyloxy, aryloxy, mercapto, alkylthio, aralkylthio, arylthio, alkylsulfonyl, aralkylsulfonyl, arylsulfonyl, alkylsulfinyl, aralkylsulfinyl, arylsulfinyl, amino, mono-or di-alkylamino, mono- or di-aralkylamino, mono- or di-arylamino, acylamino, a sulfonic acid group, nitro, alkyl, aralkyl, aryl or a heterocyclic group; R is hydrogen, alkyl, aralkyl, aryl or a heterocyclic group, with all of the alkyl, aralkyl, aryl and heterocyclic ring groups in radicals X and R optionally being substituted with at least one substituent, is purified by (a) adjusting the pH of an aqueous solution containing said cephalosporin compound to be purified to within the range of 1.0 to 3.5; (b) isolating the compound which precipitates from said solution; (c) after concentration adding the resulting mother liquor to the organic solvent, isolating the precipitated compound and agitating the obtained compound in an aqueous solution in the presence of an absorbing resin which is a hydrophilic, high molecular weight material having a fine network structure; and (d) isolating the purified compound.