FLUOROCARBON DERIVATIVES OF NITROGEN. PART 16. SYNTHESIS OF SOME UNSYMMETRICAL AROMATIC AZO-COMPOUNDS via DIAZOTISATION OF FLUORINATED ARYL- AND N-HETEROARYL-AMINES IN HYDROFLUORIC OR SULPHURIC ACID

Article abstract of DOI:10.1016/S0022-1139(00)83063-8

Coupling reactions of the type Ar_FN2⁺ + ArH -> Ar_FN=NAr + H⁺ have been accomplished between fluorinated arenediazonium ions selected from the benzenic, pyridinic and pyrimidinic classes F = C6F5, 4-CF3C6F4, 4-C5F4N, 4-C5F3N.Cl-3, 4-C5F2N.Cl2-3,5, 2-C5F3N.CF(CF3)2-4, 4-C4F3N2> and one or more aromatic compounds activated towards electrophilic attack (ArH = 1,3,5-Me3C6H3, 1,3,5-Et3C6H3, MeOC6H5, Me2NC6H5, and naphth-2-ol).The diazonium ions were generated by addition of solid sodium nitrite to solutions of the amines Ar_FNH2 in anhydrous hydrogen fluoride, 80percent hydrofluoric acid, or 98 percent sulphuric acid mixed with glacial aceticacid and propionic acid.This work has established that perfluorinated arenediazonium ions rank amongst the most electrophilic species of their general class.