Question

The type of reaction 'X' and product 'Y' of the following are respectively:
\[ {C_6H_5N_2Cl + C_6H_5NH_2 ->[\text{heat}] X -> Y} \]

• A. Electrophilic Substitution and
• B. Electrophilic Substitution and
• C. Nucleophilic Substitution and
• D. Nucleophilic Substitution and

Hint:

Azo Coupling Reactions

• Diazonium salts react with activated aromatic compounds (e.g., aniline, phenol) to form azo dyes.
• These reactions proceed via electrophilic substitution at ortho/para positions.
• Useful in the synthesis of colored compounds and indicators.

Answer 1

The Correct Option is A

This is an example of electrophilic substitution involving a diazonium salt reacting with aniline (\( \mathrm{C_6H_5NH_2} \)) to form an azo compound.

• The diazonium group (\( \mathrm{N_2^+} \)) acts as an electrophile.
• The electron-rich aniline ring undergoes coupling at the para position.
• The result is an azo dye with the structure \( \mathrm{C_6H_5{-}N{=}N{-}C_6H_4NH_2} \).

This is a classic example of azo coupling, a key method in dye chemistry.

\[ \text{X = Electrophilic Substitution}, \quad \text{Y = } \mathrm{C_6H_5{-}N{=}N{-}C_6H_4NH_2} \]

Answer 2

Understanding the reaction:

The given reaction involves the interaction between benzenediazonium chloride (\(C_6H_5N_2Cl\)) and aniline (\(C_6H_5NH_2\)) upon heating. This is a classic example of an azo coupling reaction.

Step 1: Identify the type of reaction (X)
Azo coupling is an electrophilic substitution reaction where the diazonium salt acts as an electrophile and couples with an aromatic amine (aniline) acting as the nucleophile. The diazonium ion replaces a hydrogen atom on the aromatic ring of aniline through electrophilic substitution.

Step 2: Write the product (Y)
The product formed is an azo compound where two aromatic rings are linked by an azo group (-N=N-). Specifically, the product is:
\[ \mathrm{C_6H_5{-}N{=}N{-}C_6H_4NH_2} \]
This is called an azo dye and is often brightly colored.

Step 3: Final conclusion
- The type of reaction \(X\) is electrophilic substitution.
- The product \(Y\) is the azo compound \(\mathrm{C_6H_5{-}N{=}N{-}C_6H_4NH_2}\).

Correct Answer: \(X = \text{Electrophilic Substitution}, \quad Y = \mathrm{C_6H_5{-}N{=}N{-}C_6H_4NH_2}\)