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Question #44358
The Question
Consider the following reaction sequence:
Identify the major product .
Options
- A.
4-[(3-(dimethylamino)phenyl)diazenyl]phenol
- B.
4-[(2-(dimethylamino)phenyl)diazenyl]phenol
- C.
4-[(4-(dimethylamino)phenyl)diazenyl]phenol
- D.
2-[(3-(dimethylamino)phenyl)diazenyl]phenol
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
Benzyne Intermediate (Elimination-Addition)|Ortho-Effect in Anilines|Nucleophilic Aromatic Substitution (SNAr)
Why This Question Is Tricky
Common Mistakes
This problem tests the competitive boundary between SNAr and Benzyne mechanisms, specifically exploiting the 'Ortho-Effect' and inductive stabilization in benzyne intermediates.
Students often fall into the trap of direct substitution (predicting the ortho-product) or incorrectly applying the +M resonance effect of the -NMe2 group to the benzyne intermediate.
Because the benzyne carbanion resides in an orthogonal sp2 orbital, resonance is forbidden; only the -I inductive effect and steric hindrance dictate regioselectivity, strongly favoring the meta-attack.
Furthermore, it tests chemoselectivity during diazotization, where protonation of the tertiary amine prevents anomalous nitrosation or self-coupling.
Quick Facts About This Question
Question Information
| Subject | Chemistry |
| Chapter | Haloalkanes and Haloarenes - Class 12 |
| Concept | Benzyne Intermediate (Elimination-Addition) |
| Difficulty | 8 |
| Cognitive Load | 7 |
| Target Solve Time | 160 sec |
| Access | Free |