A Novel Method. The Synthesis of Ketones and Azobenzenes Using Supported Permanganate

Abstract

The heterogeneous use of potassium permanganate, sup- ported on copper(II) sulfate pentahydrate, provides a simple and ef- fective means for oxidizing amines. Primary aliphatic amines, such as sec-butylamine, are oxidized to the corresponding carbonyl com- pounds in good to excellent yields. Primary aromatic amines, such as 4-chloroaniline, are converted quantitatively into the correspond- ing azo compounds. Carbon-carbon bond cleavage, which usually occurs when alkylbenzene side chains are oxidized by perman- ganate under homogeneous conditions, does not occur. Under ap- propriate reaction conditions carbon-hydrogen bond cleavage at the benzylic position, known to occur under heterogeneous permanga- nate conditions, is also eliminated. For example, a quantitative yield of bis(2,4,6-trimethylphenyl)diazene is obtained from the oxidation of 2,4,6-trimethylaniline using small amounts of permanganate and copper(II) sulfate pentahydrate.