Patent ID: 6835829
Filing Date: 2004-12-28
Classification: A61P,C07D

Abstract:
A process for the production of the cephalosporins cefixime or cefdinir comprising the steps ofa) depleting 7-ADCA of formula â€ƒfrom a mixture of 7-ADCA with vinyl-ACA of formula â€ƒby forming and isolating a crystalline salt of vinyl-ACA with a cation of formula â€ƒwherein R1, R2 and R3 are the same or different and independently of one another denote hydrogen, alkyl, aryl, aralkyl or cycloalkyl; or R1 and R2 together with the nitrogen atom form a 5- or 6-membered heterocycle containing one or several heteroatoms selected from the group consisting of N, S and O and R3 is as defined above; in a solvent in which the salt of 7-ADCA has a higher solubility than the salt of vinyl-ACA, wherein the solvent is selected from amides, ketones, alcohols, nitriles, esters, chlorinated hydrocarbons, water, or mixtures thereof, and wherein the salt forming agent is NR1R2R3 or an organic salt thereof, and converting said salt into vinyl-ACA in free form by adding an acid; and b) further substituting vinyl-ACA by introducing the corresponding 7-acyl group to obtain cefdinir or cefixime.