Give preparation of haloarenes from amine compounds.

Explanation

(i) Diazotization : When a primary aromatic amine, dissolved or suspended in cold aqueous mineral acid, is treated with sodium nitrite, a diazonium salt is formed. The reaction is known as diazotization.

(ii) Sandmeyer.s reaction : Mixing the solution of freshly prepared diazonium salt with cuprous chloride or cuprous bromide results in the replacement of the diazonium group by - Cl or - Br.

(iii) Iodide product : Replacement of the diazonium group by iodine does not required the presence of cuprous halide and is done simply by shaking the diazonium salt with potassium iodide.