Verfahren zur Herstellung von Cephalosporansaeurederivaten

摘要

1,237,742. Cephalosporins. CIBA-GEIGY A.G. 26 June, 1968 [5 July, 1967; 27 Oct., 1967], No. 30543/68. Heading C2A. 7 - Acylamino - 3 - acyloxymethyl - 3 - cephem-4-carboxylic acids of Formula I in which X and Y are acyl with the proviso that Y is not acetyl, and their salts, are prepared by esterifying a 3-desacetyl cephalosporin C dibenzhydryl ester of Formula II in which Bzh is benzhydryl, Z or Z-H stands for an amino protective group, with an acid Y-OH, removing the side chain in the 7- position by converting the amide group in the 7-position into an imide halide and then into an imino ether group, removing the 4-benzhydryl ester group by acid hydrolysis to form a compound of Formula III which is acylated on the 7-amino group and if desired, a resulting acid is converted into a salt or a salt into a free acid. The 4-benzhydryl group is removed by means of trifluoracetic acid in anisole. The invention comprises (A) compounds of Formula I wherein X is acyl and Y is pivaloyl (trimethylacetyl), or where X is cyanacetyl and Y is an acyl radical of an unsubstituted or halogen-substituted C 2 -C 6 alkanoic acid other than acetyl, or a salt thereof. Examples are 3-n-butyryloxymethyl-7-[thienyl- 21 - acetylamino] - ceph - 3 - em - 4 - carboxylic acid and 3-chloracetoxymethyl-7-[thienyl-21- acetylamino]-ceph-3-em-4-carboxylic acid, (B) compounds of Formula III in which Y is the acyl radical of a halogen-substituted alkanoic acid having not more than 6 carbon atoms or is a pivaloyl radical. Pharmaceutical preparations for oral, parenteral or topical use comprise a cephalosporin of Formula I and a carrier. Specifications 948,858, 1,041,985, 1,080,904, 1,141,293 and 1,205,226 are referred to.