How will you prepare chlorobenzene from benzene diazonium chloride?

To prepare chlorobenzene from benzene diazonium chloride, you can perform a Sandmeyer reaction. Here's the general procedure:

Start with benzene diazonium chloride (C6H5N2Cl) as your starting material.
Treat benzene diazonium chloride with cuprous chloride (CuCl) in the presence of hydrochloric acid (HCl) as a catalyst and a source of chloride ions.
The reaction proceeds via a diazonium ion intermediate, where the nitrogen-nitrogen (N≡N) bond is replaced by a chlorine atom from the cuprous chloride. This results in the substitution of the diazonium group (N2Cl) with a chlorine atom, leading to the formation of chlorobenzene.
The reaction is typically carried out at a low temperature to minimize side reactions and to control the formation of unwanted by-products.
After the reaction is complete, the product, chlorobenzene, can be isolated by standard techniques such as distillation or extraction.
The overall reaction can be represented as follows:

C6H5N2Cl + CuCl + HCl → C6H5Cl + N2 + CuCl2 + H2O

This method is commonly used in laboratories for the synthesis of substituted aromatic compounds.