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Question #44941

Difficulty: 8/10 | 🟢 Free

The Question

Compound \textbf{P} is 2-(tert-butyl)-4-nitroaniline. It is subjected to the following reaction sequence:

$\ce{Sn / HCl}$ , followed by neutralization with aqueous $\ce{NaOH}$ $\rightarrow$ \textbf{Q}
$\ce{PhSO2Cl}$ (1 equivalent), Pyridine, 298 K $\rightarrow$ \textbf{R} (Major Product)
$\ce{NaNO2 / HCl}$ , 273-278 K, followed by $\ce{H3PO2, H2O}$ , $\Delta$ $\rightarrow$ \textbf{S}

Identify the correct IUPAC name for the final major product \textbf{S}.

Options

A.
$N$ -(3-(tert-butyl)phenyl)benzenesulfonamide
B.
$N$ -(2-(tert-butyl)phenyl)benzenesulfonamide
C.
$N$ -(4-(tert-butyl)phenyl)benzenesulfonamide
D.
$N$ -(2-(tert-butyl)-4-nitrophenyl)benzenesulfonamide

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

Ortho-Effect in Anilines|Hinsberg Reagent Selectivity|Nucleophilic Acyl Substitution

Why This Question Is Tricky

Common Mistakes

This problem tests the 'Ortho-Effect' in the context of Hinsberg reagent selectivity.

Students often rely solely on electronic effects (assuming the +I effect of the tert-butyl group makes the ortho-amine more nucleophilic) and ignore the severe kinetic steric hindrance during nucleophilic attack on a bulky sulfonyl center.

Failing to account for this steric shielding leads to the incorrect assumption that the C1 amine reacts, which would ultimately yield the ortho-isomer (Option B) instead of the correct meta-isomer (Option A) after deamination.

Quick Facts About This Question

Question Information

Subject	Chemistry
Chapter	Amines - Class 12
Concept	Ortho-Effect in Anilines
Difficulty	8
Cognitive Load	7
Target Solve Time	160 sec
Access	Free