Which of the following can be prepared by Garbriel synthesis?

Options

A. Isobutyl amine
B. 2-phenylethylamine
C. N-methylbenzylamine
D. Aniline

Explanation

To determine which compounds can be prepared by Gabriel synthesis, we need to first understand what Gabriel synthesis is and then analyze the given compounds to identify which ones are primary amines.

### Step-by-Step Solution:

1. **Understand Gabriel Synthesis**:
- Gabriel synthesis is a method used to convert alkyl halides into primary amines. The key point here is that the product must be a primary amine.

2. **Identify the Structures of the Given Compounds**:
- We have four compounds to analyze:
- Isobutyl amine
- 2-phenyl ethylamine
- N-methyl benzylamine
- Aniline

3. **Analyze Isobutyl Amine**:
- Structure: Isobutyl amine (C4H11N) has the structure where the nitrogen is attached to one carbon chain (C3H7) and one NH2 group.
- Conclusion: This is a primary amine because the nitrogen is attached to only one carbon atom.

4. **Analyze N-Methyl Benzylamine**:
- Structure: N-methyl benzylamine has a benzyl group (C6H5-CH2-) attached to the nitrogen, along with a methyl group (CH3-).
- Conclusion: This is a secondary amine because the nitrogen is attached to two carbon groups (one from the benzyl and one from the methyl).

5. **Analyze Aniline**:
- Structure: Aniline (C6H5NH2) has an amino group (NH2) attached to a benzene ring (C6H5).
- Conclusion: Although nitrogen is attached to one carbon, it is attached to an sp2 hybridized carbon (from the benzene), which does not qualify as a primary amine in the context of Gabriel synthesis.

6. **Analyze 2-Phenyl Ethylamine**:
- Structure: 2-phenyl ethylamine has an ethyl group (C2H5) and a phenyl group (C6H5) attached to the nitrogen.
- Conclusion: This is a primary amine because the nitrogen is attached to one ethyl group and one phenyl group (the phenyl is considered as part of the carbon chain).

7. **Final Conclusion**:
- The compounds that can be prepared by Gabriel synthesis are:
- Isobutyl amine (primary amine)
- 2-phenyl ethylamine (primary amine)

### Final Answer:
The compounds that can be prepared by Gabriel synthesis are **Isobutyl amine** and **2-phenyl ethylamine**.