Question

Identify ‘A’ in the following reaction: \[ R-\text{NO}_2 \xrightarrow{\text{Zn}/\text{NH}_4\text{Cl}, \text{neutral medium}} A + \text{H}_2\text{O} \]

• A. R-N\(+\)O\(_2^-\)
• B. R-NH-OH
• C. R-COOH
• D. R-NH\(_2\)

Hint:

When reducing nitro compounds with zinc and ammonium chloride, the nitro group (-NO\(_2\)) is converted to a hydroxylamine group (-NH-OH).

Answer 1

The Correct Option is B

Step 1: Understanding the Reaction.
The reaction shown is a reduction of a nitro group (-NO\(_2\)) to a hydroxylamine group (-NH-OH) using zinc (Zn) in the presence of ammonium chloride (NH\(_4\)Cl) under neutral conditions. This reduction typically produces hydroxylamine, where the -NO\(_2\) group is reduced to -NH-OH.

Step 2: Analyzing the options.
(A) R-N\(+\)O\(_2^-\): Incorrect. This is not the product of this reduction reaction.
(B) R-NH-OH: Correct. This is the expected product when the nitro group is reduced to a hydroxylamine group.
(C) R-COOH: Incorrect. This is the product of oxidation, not reduction.
(D) R-NH\(_2\): Incorrect. This is an amine group, which would require further reduction of the hydroxylamine group, but is not the immediate product.

Step 3: Conclusion.
The correct product is R-NH-OH, corresponding to option (B).