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

1. 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.
2. 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.
3. 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.
4. 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.
5. 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.

Key Concepts

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.