Gelöste und ungelöste Probleme der Azochemie

Abstract

The elucidation of the mechanism of diazotisation by J.H. Ridd explains some unexpected reactions found in the literature (e.g. diazotisation of co-aminoalkyl-anilines, nitrosation of 2.5-dimethylaniline). Our knowledge of the role of cupric ions in the diazotisation of amino-naphthols, however, is not yet satisfactory.
New data on π-complex formation of diazonium ions with naphthalene derivatives, particularly with sulphonic acids, explain the stabilisation of diazonium salts by aromatic sulphonic acids used in azoic technology.
The mechanism of diazo coupling reactions with electrofugic leaving groups other than protons, as well as related reactions (Hünig’s oxidative coupling, the azo synthesis of Suckfüll and Dittmer etc.), are discussed.
New work by Haselbach, Heilbronner, Schetty and others on the conformation and reactions of azo compounds is described. The class of amide chlorides who became important intermediates and catalysts for various organic syntheses originated from reactions with azo compounds.