| 摘要 |
<p>An electrolytic process for removing the p-nitrobenzyl (pNB) ester protecting group from a cephalosporin 4-carboxylic acid pNB ester is described herein. The pNB ester is electrolytically reduced in an acidic liquid medium containing 0 - 50% water, an acid having a pKa (determined in water) of 0 or below, the amount of said acid being at least 4 moles per mole of compound to be reduced, and an organic solvent substantially inert to electrolytic reduction, at the working electrode of an electrolytic cell, at a temperature from about 0.degree.C to about 75.degree.C, and at a potential ranging from about the potential of the initial onset of current flow at which a first reduction takes place to about the potential of the initial onset of current flow at which a second reduction takes place. The working electrode may be made of carbon, mercury, tin, aluminum, silver, copper, lead, chromium, zinc, nickel or cadmium, and preferably is of mercury, silver or lead.</p> |
