ELECTROLYTIC PROCESS FOR PREPARING AMINOPENICILLINS

摘要

a-Aminopenicillins of Formula I and non-toxic salts thereof, wherein R is a phenyl, substituted phenyl or thienyl group, are obtained by electrolytically reducing a penicillin of Formula II wherein R is as defined above and Y is azido, arylsulphonamido, arylsulphenamido or arylcarbonylamino and m is H, a metal e.g. an alkali metal, ammonium or substituted ammonium ion. Typical groupings are azido, toluenep-sulphonamido, benzamido and o-nitrophenylsulphenamido groups. The examples relate to the preparation of ampicillin and x-amino-2- thienyl methyl penicillin. The starting penicillin and electrolyte are dissolved in a liquid solvent which will not chemically react with either the penicillin of Formula I or II, and the electrolyte solution is maintained at pH 1 to 9 during the course of the electrolysis and a metal cathode is used. The electrolyte may be a quaternary ammonium salt e.g. tetramethyl ammonium chloride, an alkali metal salt e.g. lithium chloride or an ammonium salt. The solvent may be an alcohol, an aqueous alcohol, aqueous acetone or water. The metal cathode may be of mercury, lead, zinc, silver, lead amalgam or zinc amalgam and the anode may be of graphite.