Question

Benzene diazonium chloride on reaction with aniline in presence of dilute hydrochloric acid gives:
A)

B)

C)

D)

Answer 1

Hint: Benzene diazonium chloride is an organic compound having a formula$$\text{Ar - }{{\text{N}}_{\text{2}}}^{+}\text{C}{\text{l}}^{\text{ - }}$$. It is intermediate in organic synthesis. Condensation of diazonium salts with aromatic amines in a dilute acidic solution to form azo dyes is known as coupling.


Complete solution:Aniline reacts with a mixture of sodium nitrite and hydrochloric acid and forms benzene diazonium chloride.The structure of Benzene diazonium chloride is

Benzene diazonium chloride reacts with aniline in presence of dilute hydrochloric acid and undergoes coupling reaction and produces stable azo products. In this reaction, benzene diazonium chloride acts as an electrophile in coupling with activated aniline. In this type of reaction, substitution takes place at the para position. So, the reaction Benzene diazonium chloride with aniline in presence of dilute hydrochloric acid is as follows:

Thus, the correct options are (C).

Note: Aromatic diazonium ion is a very important intermediate to produce substituted benzene. The final product depends on reagent use. The reaction given to us is the azo coupling reaction. The azo coupling reaction is widely used to produce dyes, pigments, etc. In this type of reaction, substitution at para position is more favourable. If the para position is already occupied with substituent then substitution takes place at the ortho position.