Chapter 22: Amines

Synthetically Useful Transformations Involving Aryl Diazonium Ions

• Aryl diazonium salts can be converted into a range of systems as shown above.
• These reactions can be useful as the methodology can be complementary to other methods of introducing aromatic substitutents
• Of particular note are the methods for introducing -F using HBF₄ (the Schiemann reaction) and -OH using H₂O.
• The reactions of copper salts (CuCl, CuBr and CuCN) are known as the Sandmeyer reactions.
• Coupling with phenols gives azo-compounds which are important as yellow-red dyes or pigments.
• Aryl diazonium salts are prepared from aryl amines (previous page) which in turn can be obtained by the reduction of nitrobenzene