Brian Ribbons Fishwick

Diazotisation of 4-aminotetrafluoropyridine in a sulphuric acid-acetic acid-propionic acid medium

Abstract 4-Aminotetrafluoropyridine can be diazotised successfully by adding it to a solution of sodium nitrite in a mixture of 98% sulphuric acid, acetic acid and propionic acid; addition of mesitylene, m -cresol, 3, 5-dimethylphenol or 2-naphthol to the solution of tetrafluoro-4-pyridyldiazonium ion thus produced provides the expected azo-compounds in good yields.

Thermal conversion of 2-methylphenylazo-compounds to diareno-1,2-diazepines

Abstract Examples are given of the synthesis of bis-annulated 1,2-diazepines via thermal intramolecular condensation of 2-methylphenylazo-arenes and -heteroarenes carrying an ortho ′ nucleofugal group.

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

Abstract Coupling reactions of the type Ar F N + 2 + ArH → Ar F NNAr + H + have been accomplished between fluorinated arenediazonium ions selected from the benzenic, pyridinic and pyrimidinic classes [Ar F  C 6 F 5 , 4CF 3 C 6 F 4 , 4C 5 F 4 N, 4z.sbnd;C 5 F 3 N.Cl3, 4C 5 F 2 N.Cl 2 3,5, 2C 5 F 3 N.CF(CF 3 )24, 4C 4 F 3 N 2 ] and one or more aromatic compounds activated towards electrophilic attack (ArH  1,3,5,ME 3 C 6 H 3 , 1,3,5Et 3 C 6 H 3 , MeOC 6 H 6 , and napth-2-ol). The diazonium ions were generated by addition of solid sodium nitrite to solutions of the amines Ar F NH 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.