Fluorocarbon derivatives of nitrogen. Part 16 [1]. Synthesis of some unsymmetrical aromatic azo-compounds via diazotisation of fluorinated aryl- and [formula omitted]-heteroaryl-amines in hydrofluoric or sulphuric acid [2

Abstract

Coupling reactions of the type Ar FN + 2 + ArH → Ar FNNAr + H + have been accomplished between fluorinated arenediazonium ions selected from the benzenic, pyridinic and pyrimidinic classes [Ar F  C 6F 5, 4CF 3C 6F 4, 4C 5F 4N, 4z.sbnd;C 5F 3N.Cl3, 4C 5F 2N.Cl 23,5, 2C 5F 3N.CF(CF 3)24, 4C 4F 3N 2] and one or more aromatic compounds activated towards electrophilic attack (ArH  1,3,5,ME 3C 6H 3, 1,3,5Et 3C 6H 3, MeOC 6H 6, and napth-2-ol). The diazonium ions were generated by addition of solid sodium nitrite to solutions of the amines Ar FNH 2 in anhydrous hydrogen fluoride, 80% hydrofluoric acid, or 98% sulphuric acid mixed with glacial acetic acid and propionic acid. This work has established that perfluorinated arenediazonium ions rank amongst the most electrophilic species of their general class.