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

25. Condensation Chemistry

Claisen Condensation

Organic Chemistry

25. Condensation Chemistry

Claisen Condensation

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9:49 minutes

Problem 53d

Textbook Question

Draw the products of the following reactions:
d. diethyl 1,2-benzenedicarboxylate + sodium ethoxide: (1) slow addition of ethyl acetate; (2) HCl

Verified step by step guidance

Step 1: Recognize the reaction type. This is a Claisen condensation reaction, where diethyl 1,2-benzenedicarboxylate (an ester) reacts with ethyl acetate (another ester) in the presence of a strong base (sodium ethoxide). The reaction involves the formation of a β-keto ester intermediate.

Step 2: Deprotonation of the α-hydrogen. Sodium ethoxide (NaOEt) acts as a base and deprotonates the α-hydrogen of ethyl acetate, forming an enolate ion. The enolate ion is a nucleophile that will attack the electrophilic carbonyl carbon of the diethyl 1,2-benzenedicarboxylate.

Step 3: Nucleophilic attack. The enolate ion attacks one of the ester carbonyl carbons in diethyl 1,2-benzenedicarboxylate, leading to the formation of a tetrahedral intermediate. This intermediate then collapses, expelling an ethoxide ion (EtO⁻) as a leaving group and forming a β-keto ester.

Step 4: Acidic workup. After the slow addition of ethyl acetate and completion of the reaction, the mixture is treated with HCl. The acidic workup neutralizes the base and stabilizes the β-keto ester product.

Step 5: Draw the product. The final product is a β-keto ester where the ethyl acetate has been added to the diethyl 1,2-benzenedicarboxylate framework. Ensure to include the aromatic ring and the ester groups in the structure.

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Key Concepts

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

Esterification Reaction

Esterification is a chemical reaction that forms an ester from an alcohol and a carboxylic acid. In this context, diethyl 1,2-benzenedicarboxylate reacts with sodium ethoxide, which acts as a base, facilitating the nucleophilic attack of ethyl acetate on the carbonyl carbon of the ester. This reaction is crucial for understanding how the products are formed in the given reaction sequence.

Nucleophilic Substitution

Nucleophilic substitution is a fundamental reaction mechanism in organic chemistry where a nucleophile replaces a leaving group in a molecule. In this case, the ethoxide ion acts as a nucleophile, attacking the electrophilic carbon of the diethyl 1,2-benzenedicarboxylate. Understanding this mechanism is essential for predicting the products of the reaction after the slow addition of ethyl acetate.

Acid-Base Reaction

An acid-base reaction involves the transfer of protons (H+) between reactants. After the nucleophilic substitution, the addition of HCl serves to protonate the alkoxide ion formed, converting it back to an alcohol. This step is important for completing the reaction and understanding the final products, as it influences the stability and reactivity of the intermediates.

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