Draw the product of aniline and NaNO2/HCl.
The correct answer and explanation is :
The reaction of aniline (C₆H₅NH₂) with sodium nitrite (NaNO₂) and hydrochloric acid (HCl) results in the formation of a diazonium salt, which is an intermediate in organic chemistry used for a variety of subsequent reactions. The diazonium salt formed is benzenediazonium chloride (C₆H₅N₂⁺Cl⁻).
Reaction Process:
- Step 1: Formation of Nitrous Acid (HNO₂):
In the presence of HCl, NaNO₂ reacts to produce nitrous acid (HNO₂), which is unstable and exists only in situ (i.e., within the reaction mixture).
[
NaNO_2 + HCl → HNO_2 + NaCl
] - Step 2: Formation of the Diazonium Ion:
Nitrous acid (HNO₂) then reacts with the amine group of aniline to form the diazonium ion. This step is crucial because the amine group (-NH₂) on aniline is a good nucleophile, and it reacts with the nitrous acid (HNO₂) to produce a diazonium ion. The reaction typically proceeds with the release of water and the formation of the benzenediazonium ion.
[
C_6H_5NH_2 + HNO_2 → C_6H_5N_2^+Cl^- + H_2O
] - Step 3: Product Formation:
The product of this reaction is benzenediazonium chloride (C₆H₅N₂⁺Cl⁻), which is an important intermediate in organic synthesis. This diazonium ion can be further utilized in various reactions, such as coupling reactions (forming azo dyes) or nucleophilic substitution reactions.
Overall Reaction:
[
C_6H_5NH_2 + NaNO_2 + HCl → C_6H_5N_2^+Cl^- + NaCl + H_2O
]
Explanation:
Aniline (C₆H₅NH₂) contains an amino group (-NH₂) that, when treated with sodium nitrite (NaNO₂) and hydrochloric acid (HCl), undergoes a diazotization reaction to form benzenediazonium chloride (C₆H₅N₂⁺Cl⁻). This reaction involves the formation of nitrous acid (HNO₂) in situ, which then reacts with the aniline to form the diazonium ion. This ion is highly reactive and can participate in subsequent reactions, including electrophilic aromatic substitution, making this process a key step in synthetic organic chemistry. The reaction is typically carried out at low temperatures to stabilize the diazonium ion, as it is prone to decomposition at higher temperatures.