Derivatives of cephalosporin c

The nucleus of Cephalosporin C, Cephalosporin Cc or a Cephalosporin Ca compound is prepared by treating Cephalosporin C, Cephalosporin Cc or a Cephalosporin Ca compound, such as Cephalosporin Ca (pyridine), or a derivative of any of these compounds in which the amino group of the amino-adipoyl sidechain is blocked by a grouping which is not detached therefrom during the hydrolysis and which hinders Zwitterion formation in the sidechain, with acid under such conditions and for such a time that cleavage of the sidechain or blocked sidechain from the nucleus occurs to form the corresponding nucleus and separating the nucleus so formed from the reaction products. The blocking group may be 2,4-dinitrophenyl or 2-nitro-4-carbomethoxyphenyl and the preferred acid is hydrochloric acid. Other acids which may be used include sulphonic acids and sulphonated polystyrene resins. The nucleus may be separated from the reaction products by electrophoresis, chromatography or ion exchange. The nucleus of Cephalosporin C forms salts, such as sodium, potassium and ammonium salts, on bases, and all three types of nuclei form acid addition salts at the primary amino group. The nuclei may be used in the production of new Cephalosporins by acylation of the 7-amino group. Specifications 810,196, 912,360 and 912,541 also are referred to.