Which is more basic?

Options

A. Benzylamine
B. Aniline
C. Acetamide
D. o-methyl aniline

Answer

To determine which of the given compounds is more basic, we will analyze the structures and the factors affecting the basicity of each compound. The compounds in question are benzyl amine, aniline, acetamide, and ortho methyl aniline.

### Step 1: Write the Structures
1. **Benzyl Amine**: This compound has a benzene ring attached to a -CH2-NH2 group.
- Structure: C6H5-CH2-NH2
2. **Aniline**: This compound has an amino group (-NH2) directly attached to a benzene ring.
- Structure: C6H5-NH2
3. **Acetamide**: This compound has a carbonyl group (C=O) attached to a nitrogen which is also connected to a methyl group (-CH3).
- Structure: CH3C(=O)NH2
4. **Ortho Methyl Aniline**: This compound has a methyl group in the ortho position relative to the amino group on the benzene ring.
- Structure: C6H4(NH2)(CH3) (with the methyl group on the benzene ring)

### Step 2: Analyze Basicity
- **Basicity** refers to the ability of a compound to donate a lone pair of electrons. The presence of electron-withdrawing groups or resonance effects can decrease basicity.

1. **Benzyl Amine**:
- The lone pair of electrons on the nitrogen atom is not involved in resonance with the benzene ring because it is connected through a -CH2- group. Therefore, it is more available for donation, making benzyl amine more basic.

2. **Aniline**:
- The lone pair of electrons on the nitrogen is delocalized into the benzene ring due to resonance, making it less available for donation. Thus, aniline is less basic than benzyl amine.

3. **Acetamide**:
- Similar to aniline, the lone pair on nitrogen is involved in resonance with the carbonyl group (C=O), which further decreases its basicity. Acetamide is less basic than both benzyl amine and aniline.

4. **Ortho Methyl Aniline**:
- The methyl group in the ortho position can have a slight electron-donating effect, but the lone pair on nitrogen is still involved in resonance with the benzene ring. Therefore, it is also less basic than benzyl amine.

### Conclusion
Based on the analysis, the order of basicity from most basic to least basic is:
1. **Benzyl Amine** (most basic)
2. **Aniline**
3. **Ortho Methyl Aniline**
4. **Acetamide** (least basic)

Thus, **the most basic compound is benzyl amine**.