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Question #43969
The Question
An equimolar mixture of 2-aminobenzaldehyde and ethyl 3-oxobutanoate is refluxed in the presence of catalytic aqueous at . Considering competing nucleophilic pathways and thermodynamic stability, identify the major organic product .
Options
- A.
Ethyl 2-methylquinoline-3-carboxylate
- B.
Ethyl (E)-2-acetyl-3-(2-aminophenyl)prop-2-enoate
- C.
3-acetylquinolin-2(1H)-one
- D.
Ethyl 3-(2-formylphenylamino)but-2-enoate
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
Aldol Condensation Directionality|Aniline Resonance Pitfalls|Coupling Reactivity
Why This Question Is Tricky
Common Mistakes
This problem tests the 'Aniline Resonance Pitfall' within the context of the Friedl"ander synthesis.
Students frequently halt the reaction at the acyclic aldol condensation stage (Option B), erroneously assuming that the resonance-deactivated ortho-amino group is insufficiently nucleophilic to close the ring.
The hidden variable is the massive thermodynamic driving force of forming a fully aromatic quinoline core, which easily overcomes the kinetic penalty of the delocalized aniline lone pair.
Additionally, it tests regioselectivity: the amine must selectively attack the ketone over the ester to avoid forming the incorrect quinolin-2-one derivative (Option C).
Quick Facts About This Question
Question Information
| Subject | Chemistry |
| Chapter | Aldehydes, Ketones, and Carboxylic Acids - Class 12 |
| Concept | Aldol Condensation Directionality |
| Difficulty | 8 |
| Cognitive Load | 7 |
| Target Solve Time | 160 sec |
| Access | Free |