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

26. Amines

Amines by Reduction

Organic Chemistry

26. Amines

Amines by Reduction

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3:33 minutes

Problem 48c

Textbook Question

Several additional amine syntheses are effectively limited to making primary amines. The reduction of azides and nitro compounds and the Gabriel synthesis leave the carbon chain unchanged. Formation and reduction of a nitrile adds one carbon atom. Show how these amine syntheses can be used for the following conversions.
(c) 1-bromo-3-phenylheptane → 3-phenylheptan-1-amine

Verified step by step guidance

Step 1: Recognize that the target molecule is a primary amine (3-phenylheptan-1-amine) and the starting material is 1-bromo-3-phenylheptane. This suggests that the synthesis will involve replacing the bromine atom with an amine group.

Step 2: Use the formation of a nitrile to add the amine group. Treat 1-bromo-3-phenylheptane with potassium cyanide (KCN) in an appropriate solvent (e.g., ethanol) to perform a nucleophilic substitution reaction. This will replace the bromine atom with a cyano group (-CN), forming 3-phenylheptanenitrile.

Step 3: Reduce the nitrile group (-CN) to a primary amine (-CH₂NH₂). This can be achieved using a reducing agent such as lithium aluminum hydride (LiAlH₄) in an ether solvent (e.g., diethyl ether). The reduction converts 3-phenylheptanenitrile to 3-phenylheptan-1-amine.

Step 4: Purify the product to isolate 3-phenylheptan-1-amine. Techniques such as distillation or recrystallization may be used depending on the physical properties of the compound.

Step 5: Confirm the structure of the synthesized amine using spectroscopic methods such as NMR (nuclear magnetic resonance) or IR (infrared spectroscopy) to ensure the correct functional group and carbon chain are present.

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Key Concepts

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

Amine Synthesis Methods

Amine synthesis methods are various chemical reactions used to produce amines, which are organic compounds derived from ammonia. Key methods include the reduction of azides and nitro compounds, as well as the Gabriel synthesis. Each method has specific conditions and reagents that determine the type of amine produced, such as primary, secondary, or tertiary amines.

Reduction Reactions

Reduction reactions involve the gain of electrons or the decrease in oxidation state of a molecule, often resulting in the conversion of functional groups. In the context of amine synthesis, reducing agents can convert nitro groups to amines or azides to amines, effectively transforming the starting material while maintaining the carbon skeleton. Understanding these reactions is crucial for manipulating organic compounds.

Nitrile Formation and Reduction

Nitrile formation involves the introduction of a cyano group (-C≡N) into a molecule, which can be achieved through various methods, such as nucleophilic substitution. The subsequent reduction of nitriles can yield primary amines, adding a carbon atom to the chain. This process is significant in organic synthesis, allowing for the construction of complex amine structures from simpler precursors.

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Related Practice

Textbook Question

Show how to prepare the following aromatic amines by aromatic nitration, followed by reduction. You may use benzene and toluene as your aromatic starting materials.

(d) m-aminobenzoic acid

Textbook Question

Show how you can synthesize the following compounds starting with benzene, toluene, and alcohols containing no more than four carbon atoms as your organic starting materials. Assume that para is the major product (and separable from ortho) in ortho, para mixtures.

(g) 4-isobutylaniline

Textbook Question

Using any necessary reagents, show how you can accomplish the following multistep syntheses.

(b)

Textbook Question

Show how you would accomplish the following synthetic conversions.

(a) benzyl bromide → benzylamine

Textbook Question

Starting with cyclohexene, how can the following compounds be prepared?

b. cyclohexylmethylamine

Textbook Question

How could you convert N-methylbenzamide to the following compounds?