A Novel Method. The Synthesis of Ketones and Azobenzenes Using Supported Permanganate~1

摘要

The heterogeneous use of potassium permanganate, supported on copper(II) sulfate pentahydrate, provides a simple and effective means for oxidizing amines. Primary aliphatic amines, such as sec-butylamine, are oxidized to the corresponding carbonyl compounds in good to excellent yields. Primary aromatic amines, such as 4-chloroaniline, are converted quantitatively into the corresponding azo compounds. Carbon-carbon bond cleavage, which usually occurs when alkylbenzene side chains are oxidized by permanganate under homogeneous conditions, does not occur. Under appropriate reaction conditions carbon-hydrogen bond cleavage at the benzylic position, known to occur under heterogeneous permanganate 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.