AROMATIC SUBSTITUTION: PART IX. ON THE MECHANISM OF THE PSCHORR CYCLIZATION

Abstract
The decomposition of the diazonium salt from 3-(o-aminobenzoyl)pyridine has been studied under various conditions. A competitive-type cyclization of an equimolar mixture of the diazonium salts of 2-aminobenzophenone and 2-amino-3′-nitrobenzophenone has also been carried out. The results are interpreted in terms of a radical process in the copper-catalyzed reactions. It is suggested that the uncatalyzed thermal decompositions in aqueous acid solution give rise to a diradical cation intermediate in equilibrium with the aryl cation.