CONVERSION OF PENICILLINS AND CEPHALOSPORINS TO 1-(S)-SULFOXIDES

摘要

The present application discloses a process for the conversion of penicillin-1-(R)-sulfoxide(s) and/or cephalosporin-1-(R)-sulfoxides in solution, to their corresponding 1-(S)-sulfoxides comprising the step of treating said 1-(R)-sulfoxide with a sufficient amount of an acid anhydride to convert at least some of said 1-(R)-sulfoxide to its corresponding 1-(S)-sulfoxide. Also disclosed is a process for the production of 1-(S)-sulfoxide from penicillin and/or cephalosporin by oxidizing the penicillin or cephalosporin with an oxidizing agent and simultaneously or subsequently adding a sufficient amount of an acid anhydride to convert at least some 1-(R)-sulfoxide to its corresponding 1-(S)-sulfoxide over a time period of from 5 minutes to 2 hours so as to maintain the pH above 3.5 and produce a solution of the corresponding 1-(S)-oxide. In a preferred embodiment, a buffer is incorporated in the solution to provide additional pH control during the reaction. The process produces exceptionally high yields of high purity 1-(S)-oxides and is safer than most commercial processes which require the use and handling of 40 % peracetic acid.