Diazotization–cyanation of aromatic amines with crosslinked poly(4-vinylpyridine)-supported cyanide ions

A simple, mild, and efficient method for the cyanation of stable arenediazonium salts was developed with polymer-supported cyanide. Arenediazonium hydrogen sulfate (Ar? N₂⁺HSO₄^?) was obtained by the reaction between a primary aryl amine and sodium nitrite in the presence of concentrated sulfuric acid (H₂SO₄) at low temperature (0–5°C). By an ion-exchange reaction between Ar? N₂⁺HSO₄^? and NaBF₄, the stable arenediazonium tetrafluoroborate, Ar? N₂⁺BF₄^?, was prepared. Ar? N₂⁺BF₄^? was then converted to aryl nitrile with crosslinked poly(4-vinylpyridine) supported cyanide ion in acetonitrile at room temperature. The spent polymeric reagent was regenerated and reused several times without any loss in its activity. This procedure offered advantages, including a higher isolated yield, shorter reaction time, and simple reaction workup. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012