GB606482A - Improvements in and relating to the purification of penicillin salts - Google Patents

Abstract

Pure penicillin is prepared by a process in which free penicillin dissolved in a solvent is treated with a primary amine. The resultant precipitate of a penicillin primary amine salt may be converted into corresponding metallic salts. It has been found desirable to dissolve the penicillin in a main solvent, subsequently to add a secondary solvent and finally to add the primary amine. Suitable primary amines are cyclohexylamine, 2, 3 or 4 methyl cyclohexyl amine, monoethylamine, isopropylamine and n-butylamine. Preferred main solvents are ether, amyl acetate, methyl isobutyl ketone and, using a modified process, chloroform. Preferred secondary solvents are ethyl alcohol, acetone and methyl ethyl ketone. In examples: (I) and (IV) an ethereal extract of an acidified penicillin solution was diluted with acetone and treated with cyclohexylamine; (II) the cyclohexylamine salt was similarly prepared using methyl isobutyl ketone as the solvent, and (III) the isopropylamine salt was prepared using ether as the main solvent with acetone as a secondary solvent.