What is the product formed when Aniline reacts with Phosgene? 

Phenyl isocyanate 

The correct answer is option 3. Phenyl isocyanate.

Aniline is an aromatic amine, and phosgene is a chemical compound that is widely used in organic synthesis. When aniline reacts with phosgene, the following reaction occurs:

Steps of the Reaction:

Formation of Phenyl Isocyanate \((C_6H_5NCO)\):

Aniline reacts with phosgene , leading to the substitution of the hydroxyl group in phosgene with the amino group of aniline. This substitution results in the formation of phenyl isocyanate \((C_6H_5NCO)\) and hydrochloric acid \((HCl)\) as a by-product. The isocyanate functional group \((-NCO)\) is formed where the nitrogen is doubly bonded to carbon, with the oxygen bearing a lone pair.

Nature of Phenyl Isocyanate:

Phenyl isocyanate \((C_6H_5NCO)\) is an aromatic isocyanate compound. It is characterized by its reactivity towards nucleophiles, such as amines and alcohols, due to the electrophilic nature of the carbon atom in the isocyanate group.

Significance and Applications:

Organic Synthesis: Phenyl isocyanate is used as a versatile intermediate in organic synthesis.

Polyurethane Chemistry: Isocyanates are crucial in the production of polyurethanes, where they react with polyols to form polyurethane polymers.

Pesticides and Pharmaceuticals: Isocyanates are also used in the synthesis of certain pesticides and pharmaceuticals.

Conclusion: In summary, when aniline reacts with phosgene, the main product formed is phenyl isocyanate \((C_6H_5NCO)\). This reaction is important in organic chemistry for its role in synthesizing various compounds and materials, particularly in the production of polyurethanes and other industrially significant chemicals.