For example, can I convert chlorobenzene into benzonitrile by using potassium cyanide as the reagent?

  • 1
    $\begingroup$ Replacing Cl in with CN is benzene can be done but requires a catalyst. Uncatalysed nothing with happen. $\endgroup$
    – Waylander
    Nov 19, 2018 at 19:28
  • $\begingroup$ Can you please tell me the catalyst $\endgroup$
    – SLADE
    Nov 19, 2018 at 20:08
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    $\begingroup$ There are many sets of conditions in the literature using Pd or Ni catalysis, more info here organic-chemistry.org/synthesis/C1C/arenes/cyanations.shtm $\endgroup$
    – Waylander
    Nov 19, 2018 at 21:04
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    $\begingroup$ If possible, you'd rather start with iodoarenes. One of the well-established method uses copper(I) cyanide. Please see my answer to an earlier question, chemistry.stackexchange.com/questions/63892/… $\endgroup$ Nov 20, 2018 at 5:51

1 Answer 1


Chlorobenzene is generally inert to nucleophilic substitution. It was observed by Rosenmund and Braun that using an ethanolic solution of potassium cyanide and cuprous cyanide as catalyst at 200°C, chlorobenzene converts to benzoic acid. But if the ethanol-cyanide solvent is removed and temperature is raised, then the reaction proceeds to form cyanobenzene. Yield was further improved when ionic liquids like DMF was used. This is Rosenmund-Braun reaction.

Note: Working with cyanide is highly dangerous. Do not handle cyanide until and unless you are a professional chemist.


  1. Wikipedia: Rosenmund-von Braun reaction
  2. Will cyanide substitute bromine in bromobenzene?
  3. Potassium ferrocyanide, $\ce{K4[Fe(CN)6]}$ can be used as a non-toxic source for cyanation.
  4. There are loads of other catalyst for cyanation like $\ce{ZnCl2}$, palladium or nickel salts.[@Waylander]

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