Patent ID: 6518420
Filing Date: 2003-02-11
Classification: C07D

Abstract:
A process for the precipitation of 7-ACA of formula comprisinga) providing an alkaline, neutral or slightly acidic solution of the corresponding 7-ACA carboxylate with a pH above the isoelectric point of 7-ACA b) adding an acid to the solution in an amount sufficient to precipitate the 7-ACA in the presence of an additive being selected from the group consisting of organic carboxylic acid esters, polyacrylates, polymeric glycols and amino acids of formula R10â€”CHâ€”(NR2R4)â€”COOR1â€ƒâ€ƒVIII wherein R10 denotes hydrogen, unsubstituted or substituted alkyl, unsubstituted or substituted aryl or a group of formula â€”(CH2)mâ€”Xâ€”R5, and R1, R2, R4 and R5 are the same or different and represent hydrogen, unsubstituted or substituted lower alkyl, phenyl, (mono-tri)hydroxyphenyl or lower alkylphenyl, X denotes â€”Oâ€” or â€”NR4, and m is a whole number from 0 to 6.