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Question #44046

Difficulty: 8/10 | 🟢 Free

The Question

Compound $\mathbf{X}$ is 4-aminobenzylamine. It is subjected to the following reaction sequence:

$\mathbf{X} \xrightarrow[\text{0-5}^\circ\text{C}]{\text{NaNO}_2 \text{ (1 eq.), dil. HCl (excess)}} \mathbf{Y}$
$\mathbf{Y} \xrightarrow[\text{0-5}^\circ\text{C}]{\beta\text{-naphthol, NaOH (excess)}} \mathbf{Z}$
$\mathbf{Z} \xrightarrow{\text{CHCl}_3\text{, KOH, }\Delta} \mathbf{W} \text{ (Major Product)}$

Identify the correct IUPAC name for the major product $\mathbf{W}$ .

Options

A.
1-[(4-isocyanomethylphenyl)diazenyl]naphthalen-2-ol
B.
1-(4-isocyanobenzyl)naphthalen-2-ol
C.
1-[(4-isocyanomethylphenyl)diazenyl]-3-formylnaphthalen-2-ol
D.
1-[(4-aminomethylphenyl)diazenyl]naphthalen-2-ol

Check Your Answer

Correct Answer

Step-by-Step Solution

Explanation

How the Examiner Thinks

Mechanism_Trap

Don't get tricked by the process! Learn the mechanical traps used in competitive exam questions.

Concepts Behind This Question

Carbylamine Reaction Specificity|Aniline Resonance Pitfalls|Diazotization Temperature Sensitivity

Why This Question Is Tricky

Common Mistakes

The problem tests the student's grasp of pH-dependent chemoselectivity and competing reaction conditions.

The 'Hidden Variable' is the protonation state of the two primary amines during diazotization; students often mistakenly assume the more nucleophilic aliphatic amine will react first, failing to realize it is completely deactivated as an ammonium salt in the acidic medium.

Furthermore, it tests the 'Chemical Exception' that Reimer-Tiemann formylation is suppressed in azo-naphthol dyes due to hydrazone tautomerism and electronic deactivation, isolating the Carbylamine reaction as the sole transformation in the final step.

Quick Facts About This Question

Question Information

Subject	Chemistry
Chapter	Amines - Class 12
Concept	Carbylamine Reaction Specificity
Difficulty	8
Cognitive Load	7
Target Solve Time	160 sec
Access	Free