Patent ID: 7560545

Claim:
A process for obtaining cefotetan of formula (I) containing not more than 0.2% of the acid form of the tautomer of formula (II) wherein H appears in place of Na wherein the cefotetan has a K.F up to 2.5%, and a purity on dry basis at least 99.0%, wherein an aqueous solution of crude cefotetan cooled to between 0° and +4° C. is brought into contact with Al 3+ ions originating from a reagent chosen from the group consisting of neutral alumina, anhydrous aluminium trichloride and aluminium trichloride hexahydrate, or with Fe 3+ or Cr 3+ ions, to cause formation of a precipitate with the aforesaid tautomer compound, at pH within the range 7.0-7.2, this precipitate being eliminated by filtration to provide a solution containing cefotetan of high purity, from which the cefotetan is precipitated by acidification at pH within the range 1.3-1.5 and isolated by filtration between 0° and +4° C. to provide a cefotetan with a K.F. up to 2.5%, and having a purity on a dry basis of at least 99.0%.