Question

What are the products N and Q in the following reaction sequences?

• A. A
• B. B
• C. C
• D. D

Hint:

Stephen reduction is a very selective method to convert nitrilies (\(-\text{CN}\)) to aldehydes (\(-\text{CHO}\)).
Similarly, the Gattermann-Koch reaction is a standard method to formylate benzene to benzaldehyde.
Recognizing these named reactions helps solve multi-step synthesis questions instantly.

Answer 1

The Correct Option is A

To determine the products N and Q in the given reaction sequences, we must analyze the chemical processes involved.

1. Reaction Pathway for N:
   1. The first step starts with an aniline derivative where the diazonium salt \(C_6H_5N_2^+Cl^−\) reacts with \(H_3PO_2\) and \(H_2O\). This is a known reaction for reducing diazonium salts to form benzene, represented here as \(M = C_6H_6\).
   2. The second step is a Gattermann-Koch formylation reaction where benzene reacts with CO, HCl, and anhydrous AlCl₃ to produce benzaldehyde \(C_6H_5CHO\), which is N.
2. Reaction Pathway for Q:
   1. The starting material is benzonitrile \(C_6H_5CN\).
   2. This undergoes reduction with SnCl₂ and HCl to form an imine \(P = C_6H_5CH=NH\) followed by hydrolysis to yield benzaldehyde \(C_6H_5CHO\), which is Q.

Based on this analysis, both products N and Q are benzaldehyde:

• N = Q = C₆H₅CHO (Benzaldehyde)

Therefore, the correct answer is Option A.