What is sandmeyer reaction class 12

What is Sandmeyer's reaction class 12

Sandmeyer reaction describes the chemical transformation of aryl diazonium salt into aryl halides using copper salts as reagents or catalysts. It is an example of radical-nucleophilic aromatic substitution.

As for preparing fluorides and iodides, Sandmeyer's reaction is not particularly helpful, but it is probably the best way of introducing bromine or chlorine into an aromatic ring.

In 1884, Sandmeyer attempted to synthesize phenylacetylene from benzene diazonium chloride and copper(I) acetylide. Instead, he isolated chlorobenzene as the main product. That is why this reaction is known as the Sandmeyer reaction.

Application of Sandmeyer reaction

Modifications (within certain limits) have been done in the Sandmeyer reaction to fit many synthetic applications. 

According to the scheme below, these reactions usually begin by forming aryl diazonium salts, followed by a reaction with copper (I) salts to yield substituted arenes.

Some examples of the synthetic applications of the Sandmeyer reaction are provided below.

1. Halogenation

There are many important uses of the Sandmeyer reaction. Halogenation is one of them. Diiodomethane is the preferred solvent for the synthesis of iodoarenes. Bromoform is the preferred solvent for bromoarenes. On the other hand, chloroform is the preferred solvent for the synthesis of chloroarenes. 

2. Cyanation

Sandmeyer reactions may also be used for cyanation, enabling the production of benzonitriles.

In chemistry, benzonitrile has the formula C6H5(CN), abbreviated PhCN.

3. Hydroxylation

It is also possible to convert aryl amines to phenols via the Sandmeyer reaction, as shown below.