Question

What happens when chlorobenzene is heated with aqueous ammonia in the presence of cuprous oxide at 475 K and under high pressure?

Answer 1

When chlorobenzene is heated with aqueous ammonia in the presence of cuprous oxide (Cu₂O) at 475K and under high pressure, the following occurs:

1. The reaction leads to the substitution of the chlorine atom by an amino group (-NH₂).
2. This process is an example of nucleophilic aromatic substitution catalyzed by cuprous oxide.
3. The product formed is aniline (C₆H₅NH₂).
4. The balanced chemical equation for the reaction is:
   \[\mathrm{C_6H_5Cl} + 2\mathrm{NH_3} \xrightarrow[\text{high pressure}]{\mathrm{Cu_2O}, 475K} \mathrm{C_6H_5NH_2} + \mathrm{NH_4Cl}\]
5. Here, the chlorine atom is replaced by the amino group from ammonia, and ammonium chloride (NH₄Cl) is formed as a byproduct.
6. This reaction is important for the industrial synthesis of aniline, which is a key intermediate in dyes and pharmaceuticals.

Thus, chlorobenzene reacts with aqueous ammonia under these conditions in the presence of cuprous oxide catalyst to yield aniline and ammonium chloride.