GB808971A - Derivatives of cephalosporin n - Google Patents

Abstract

The invention relates to derivatives of Cephalosporin-N wherein a functional derivative of an organic acid radical is condensed with the amino group of the Cephalosporin-N. By functional derivative of an organic acid radical is meant a substance which is reactive with an amine to produce a condensation product resembling a condensation product obtainable or theoretically obtainable with the acid itself. Specified are dithio-acids, e.g. dithiophenylacetic acid, acid chlorides, acid anhydrides, e.g. acetic anhydride, sulphonyl halides, isocyanates, e.g. phenylisocyanate, isothiocyanates, and the functional derivatives of benzoic acid, e.g. benzazyl chloride, benzene sulphonic acid and p-aminobenzene sulphonic acid. Peptide linked products may be produced by using mixed anhydrides of carboxylic acids containing protected amino groups in which the amino group is substituted by e.g. carboxymethyl radicals and acids of formula HX where X is an acid radical, e.g. sulphate. The condensation is preferably carried out at a pH above 5 and preferably 6 to 7 and at temperatures of below 10 DEG C. especially in aqueous solution, e.g. aqueous sodium bicarbonate. In the Cephalosporin-N residues which form part of the condensation product, the acid groups may be present as such or may have their replaceable hydrogen atoms replaced by metallic especially alkali metals, e.g. sodium or other salt-forming substituent groups. Examples describe the following derivatives of Cephalosporin-N (a) benzoyl, (b) carbobenzyloxy, (c) acetyl, and (d) phenylisocyanate. Specification 745,208 is referred to.