A new amine salt of penicillin g

The N-benzyl-beta-phenylethylamine salt of penicillin G is prepared by reacting penicillin G ions with N-benzyl-beta-phenylethylamine ions in a solvent in which the said salt is relatively insoluble whilst the starting materials are more soluble than the said salt. The salt may be prepared by reacting (a) the free amine with the free penicillin G in the presence of a solvent such as t-butanol, acetone, or ethyl, butyl or amyl acetate; (b) a salt of the amine, e.g. hydrochloride with a salt of penicillin G, e.g. sodium salt in the presence of water; and (c) the free penicillin with the salt of the amine and an aliphatic or substituted aliphatic acid containing not more than 8 carbon atoms in a straight chain, e.g. formic, acetic, propionic, butyric, isobutyric, isocaproic, caprylic, 2-ethylhexoic, phenylacetic, glycollic or malonic acids, in the presence of an organic solvent such as diethyl ether, methyl isobutyl ketone, or ethyl, butyl or amyl acetate. The salt may be used in the purification of penicillin from e.g. solvent extracts, buffered alkaline extracts and crystallization mother liquors. It is used in medicine (see Group VI) and is an animal feed supplement (see Group I).ALSO:The N-benzyl-beta-pehnylethylamine salt of penicillin G (see Group IV (b)) is sufficiently stable to be useful as a supplement to animal feeds.ALSO:The N-benzyl-beta-phenylethylamine salt of penicillin G (see Group IV (b)) may be administered (a) orally in a flavoured mixture, or (b) injected in an aqueous medium containing polyoxyethylene monoleate.