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

22. Carboxylic Acid Derivatives: NAS

Carboxylic Acid to Acid Chloride

Organic Chemistry

22. Carboxylic Acid Derivatives: NAS

Carboxylic Acid to Acid Chloride

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7:42 minutes

Problem 57d

Textbook Question

Using an alcohol for one method and an alkyl halide for the other, show two ways to make each of the following esters:
d. methyl phenylethanoate (odor of honey)

Verified step by step guidance

Step 1: Understand the structure of methyl phenylethanoate. It is an ester with the formula CH₃OCOCH₂C₆H₅. The ester functional group consists of a carbonyl group (C=O) bonded to an oxygen atom, which is further bonded to a methyl group (CH₃). The phenylethanoate portion contains a phenyl group (C₆H₅) attached to a two-carbon chain.

Step 2: Method 1 - Using an alcohol: To synthesize methyl phenylethanoate, start with phenylacetic acid (C₆H₅CH₂COOH) as the carboxylic acid. React phenylacetic acid with methanol (CH₃OH) in the presence of an acid catalyst, such as sulfuric acid (H₂SO₄). The acid catalyst promotes the esterification reaction, where the hydroxyl group (-OH) of the carboxylic acid is replaced by the methoxy group (-OCH₃) from methanol, forming the ester.

Step 3: Method 2 - Using an alkyl halide: Begin with phenylacetic acid (C₆H₅CH₂COOH) as the carboxylic acid. First, convert phenylacetic acid into its carboxylate salt by reacting it with a base, such as sodium hydroxide (NaOH), to form sodium phenylacetate (C₆H₅CH₂COO⁻Na⁺). Then, perform an SN2 reaction between sodium phenylacetate and methyl iodide (CH₃I). The methyl group from methyl iodide replaces the sodium ion, forming methyl phenylethanoate.

Step 4: Highlight the reaction conditions: For the esterification method using an alcohol, ensure the reaction is carried out under reflux to drive the equilibrium toward ester formation. For the alkyl halide method, ensure the reaction is performed in a polar aprotic solvent, such as acetone, to facilitate the SN2 mechanism.

Step 5: Summarize the two methods: The first method involves direct esterification of phenylacetic acid with methanol under acidic conditions. The second method involves converting phenylacetic acid to its carboxylate salt, followed by an SN2 reaction with methyl iodide. Both methods yield methyl phenylethanoate as the final product.

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Key Concepts

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

Esterification

Esterification is a chemical reaction that forms an ester from an alcohol and a carboxylic acid. This process typically involves the removal of a water molecule (condensation reaction) and can be catalyzed by an acid. Understanding this reaction is crucial for synthesizing esters, such as methyl phenylethanoate, from the appropriate reactants.

Nucleophilic Substitution

Nucleophilic substitution is a fundamental reaction mechanism in organic chemistry where a nucleophile replaces a leaving group in a molecule. In the context of ester synthesis, alkyl halides can undergo nucleophilic substitution with alcohols to form esters. This concept is essential for understanding how to create esters using alkyl halides.

Reactivity of Alcohols and Alkyl Halides

The reactivity of alcohols and alkyl halides is pivotal in ester formation. Alcohols can act as nucleophiles, while alkyl halides serve as electrophiles. The choice of specific alcohols and alkyl halides influences the efficiency and outcome of the esterification process, making it important to select the right reactants for synthesizing methyl phenylethanoate.

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