Question

Write a note on Sandmeyer’s reaction. 

OR 

How is aryl chloride or aryl bromide or aryl cyanide prepared from diazonium salt?

Answer 1

[Replacement by Cl^-, Br^- and -CN : Sandmeyer reaction.] 

Freshly prepared aromatic diazonium salt on reaction with cuprous chloride gives aryl chloride, on reaction with cuprous bromide gives aryl bromide and on reaction with cuprous cyanide give aryl cyanide. 

The reaction in which copper (I) salts are used to replace nitrogen in diazonium salt is called Sandmeyer reaction.