Studies on Sulfenamides. VII. Anodic Oxidation of 3'-and 2'-Substituted 2-Nitrobenzenesulfenanilides

Abstract

Controlled potential electrolysis of 2'-(p-chlorophenyl) amino-4'-chloro-2-nitrobenzene-sulfenanilide (4c) gave 2, 7-dichlorophenazine in good yield. This result suggested that in the electrolysis of 4'-substituted 2-nitrobenzenesulfenanilides the ring closure to form the 2, 7-disubstituted phenazines takes place through the binding of the nitrenium ion (B) to the 2'-position of the sulfenanilides. As for the 3'-and 2'-substituted 2-nitrobenzene-sulfenanilides, most of the nitrenium ions bind to the 4'-position and are oxidized further to the p-quinonediimine derivatives, and most of these are oxidized further to unidentified resinous compounds.