The best reagent for converting 2-phenylpropanamide into 2-phenylpropanamine is….

Options

A. excess H2
B. `Br_(2)` in aqueous NaOH
C. iodine in the presence of red phosphorus
D. `LiAlH_(4)` in ether

Explanation

To convert 2-phenylpropanamide into 2-phenylpropanamine, we need to remove the carbonyl group (C=O) from the amide functional group (–C(=O)NH2) and replace it with an amine (–NH2) group. The best reagent for this transformation is lithium aluminum hydride (LiAlH4) in ether. Here’s the step-by-step solution:

### Step 1: Identify the Functional Groups
- **Starting Compound**: 2-phenylpropanamide (C6H5-CH(CH3)-C(=O)-NH2)
- **Target Compound**: 2-phenylpropanamine (C6H5-CH(CH3)-NH2)

### Step 2: Understand the Reaction
- The reaction involves the reduction of the amide group to an amine group. This means we need to convert the carbonyl (C=O) of the amide into an amine (–NH2).

### Step 3: Choose the Reagent
- The best reagent for this conversion is lithium aluminum hydride (LiAlH4). This reagent is a strong reducing agent that can effectively reduce the carbonyl group in amides to amines.

### Step 4: Set Up the Reaction Conditions
- The reaction should be carried out in an ether solvent, which is suitable for the lithium aluminum hydride to dissolve and react with the amide.

### Step 5: Perform the Reaction
- Add lithium aluminum hydride to the 2-phenylpropanamide in an ether solvent. The LiAlH4 will donate hydride ions (H-) to the carbonyl carbon, effectively reducing it to an amine.

### Step 6: Work Up the Reaction
- After the reaction is complete, quench the reaction mixture with water or a dilute acid to destroy any excess LiAlH4 and to protonate the amine product.

### Step 7: Isolate the Product
- Finally, isolate the 2-phenylpropanamine from the reaction mixture, typically through extraction and purification techniques.

### Final Answer
The best reagent for converting 2-phenylpropanamide into 2-phenylpropanamine is lithium aluminum hydride (LiAlH4) in ether.

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