Table of contents

1. A Review of General Chemistry5h 5m
2. Molecular Representations1h 14m
3. Acids and Bases2h 46m
4. Alkanes and Cycloalkanes4h 17m
5. Chirality3h 39m
6. Thermodynamics and Kinetics1h 22m
7. Substitution Reactions1h 48m
8. Elimination Reactions2h 30m
9. Alkenes and Alkynes2h 9m
10. Addition Reactions3h 19m
11. Radical Reactions1h 58m
12. Alcohols, Ethers, Epoxides and Thiols2h 42m
13. Alcohols and Carbonyl Compounds2h 17m
14. Synthetic Techniques1h 26m
15. Analytical Techniques:IR, NMR, Mass Spect7h 3m
16. Conjugated Systems6h 13m
17. Ultraviolet Spectroscopy51m
18. Aromaticity2h 34m
19. Reactions of Aromatics: EAS and Beyond5h 1m
20. Phenols55m
21. Aldehydes and Ketones: Nucleophilic Addition4h 56m
22. Carboxylic Acid Derivatives: NAS2h 51m
23. The Chemistry of Thioesters, Phophate Ester and Phosphate Anhydrides1h 10m
24. Enolate Chemistry: Reactions at the Alpha-Carbon1h 53m
25. Condensation Chemistry2h 9m
26. Amines1h 43m
27. Heterocycles2h 0m
28. Carbohydrates5h 53m
29. Amino Acids4h 20m
30. Peptides and Proteins2h 42m
31. Catalysis in Organic Reactions1h 30m
32. Lipids 2h 50m
33. The Organic Chemistry of Metabolic Pathways2h 52m
34. Nucleic Acids1h 32m
35. Transition Metals6h 14m
36. Synthetic Polymers1h 49m

21. Aldehydes and Ketones: Nucleophilic Addition

Imine vs Enamine

Organic Chemistry

21. Aldehydes and Ketones: Nucleophilic Addition

Imine vs Enamine

Previous problemNext problem

5:24 minutes

Problem 5d

Textbook Question

Draw the product of each of the following reactions:
d.

Verified step by step guidance

Step 1: Identify the reactants. The left structure is a ketone (2-pentanone), and the right structure is an amine (ethylamine). The reaction occurs in the presence of HCl, which acts as a catalyst.

Step 2: Recognize the type of reaction. This is an imine formation reaction, where a ketone reacts with a primary amine under acidic conditions to form an imine.

Step 3: Understand the mechanism. The ketone undergoes nucleophilic attack by the amine, forming a tetrahedral intermediate. Protonation and dehydration follow, leading to the formation of the imine.

Step 4: Predict the product structure. Replace the oxygen of the ketone with the nitrogen from the amine, and attach the ethyl group to the nitrogen. The double bond forms between the carbon and nitrogen.

Step 5: Verify the stereochemistry and connectivity. Ensure the carbon-nitrogen double bond is correctly placed, and the ethyl group is bonded to the nitrogen atom in the final imine product.

Verified video answer for a similar problem:

This video solution was recommended by our tutors as helpful for the problem above

Video duration:

Play a video:

Was this helpful?

Key Concepts

Here are the essential concepts you must grasp in order to answer the question correctly.

Imine Formation

Imine formation occurs when a carbonyl compound, such as an aldehyde or ketone, reacts with an amine. The reaction involves the nucleophilic attack of the amine on the carbonyl carbon, leading to the formation of a tetrahedral intermediate. This intermediate then loses a water molecule, resulting in the formation of an imine, characterized by a C=N bond.

Enamine Formation

Enamines are formed when a carbonyl compound reacts with a secondary amine. Similar to imine formation, the amine attacks the carbonyl carbon, forming a tetrahedral intermediate. However, in this case, the intermediate undergoes dehydration to yield an enamine, which features a C=C bond adjacent to a nitrogen atom, providing unique reactivity in organic synthesis.

Role of HCl in Reactions

Hydrochloric acid (HCl) serves as a catalyst in the formation of imines and enamines by protonating the carbonyl oxygen. This protonation increases the electrophilicity of the carbonyl carbon, facilitating the nucleophilic attack by the amine. Additionally, HCl can help drive the dehydration step, promoting the formation of the final imine or enamine product.

Watch next

Master General Reactions with a bite sized video explanation from Johnny

Start learning