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Question #44035

Difficulty: 8/10 | 🟢 Free

The Question

Consider the following reaction sequence:

$\text{Compound \textbf{A} (3,5-dimethyl-4-nitrobenzamide)} \xrightarrow[\Delta]{\ce{Br2 (1 eq.) / NaOH}} \textbf{B}$ $\textbf{B} \xrightarrow{\ce{Sn / HCl}} \xrightarrow{\ce{NaOH (aq)}} \textbf{C}$ $\textbf{C} \xrightarrow[\text{Pyridine, } 0^\circ\text{C}]{\ce{CH3COCl} \text{ (1 eq.)}} \textbf{D} \text{ (Major Product)}$

Identify the IUPAC name of the major product \textbf{D}.

Options

A.
\ce{N-(4-amino-3,5-dimethylphenyl)acetamide}
B.
\ce{N-(4-amino-2,6-dimethylphenyl)acetamide}
C.
\ce{4-acetamido-3,5-dimethylbenzamide}
D.
\ce{N,N'-(2,6-dimethyl-1,4-phenylene)diacetamide}

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

Hoffmann Bromamide Rearrangement|Ortho-Effect in Anilines|Nucleophilic Acyl Substitution

Why This Question Is Tricky

Common Mistakes

The question tests the interplay between electronic and steric effects in nucleophilic aromatic amines, combined with atom-tracking through a multi-step synthesis.

The critical trap lies in the final acylation step: the amine flanked by two methyl groups is electronically more nucleophilic (due to +I and hyperconjugation from ortho-methyls) but sterically hindered.

Students relying solely on electronic effects will incorrectly choose the hindered amine for acylation (Option B).

The 'Ortho Effect' (steric hindrance) dominates the kinetics of nucleophilic acyl substitution, directing the acetyl group to the less electron-rich but unhindered amine.

Quick Facts About This Question

Question Information

Subject	Chemistry
Chapter	Amines - Class 12
Concept	Hoffmann Bromamide Rearrangement
Difficulty	8
Cognitive Load	7
Target Solve Time	160 sec
Access	Free