Amongest the following the most basic compounds is-

Options

A. p-nitro aniline
B. acetanilide
C. Aniline
D. Benzylamine

Answer

To determine which of the given compounds is the most basic, we need to analyze the structure and the electronic effects of each compound. Let's break it down step by step.

### Step 1: Identify the Compounds
The four compounds provided are:
1. Para-nitroaniline
2. Acetanilide
3. Aniline
4. Benzylamine

### Step 2: Understand Basicity
Basicity in organic compounds, especially amines, is primarily due to the availability of the lone pair of electrons on the nitrogen atom. The more available this lone pair is for donation, the stronger the base.

### Step 3: Analyze Each Compound
- **Para-nitroaniline**: The presence of the nitro group (-NO2) is an electron-withdrawing group. This group pulls electron density away from the nitrogen, making the lone pair less available for donation. Thus, it decreases the basicity.

- **Acetanilide**: In this compound, the nitrogen is bonded to a carbonyl group (C=O) and a methyl group (CH3). The carbonyl group also withdraws electron density from the nitrogen through resonance, which reduces the availability of the lone pair for donation. Therefore, it is less basic.

- **Aniline**: Aniline has a lone pair on nitrogen that is partially delocalized into the aromatic ring due to resonance. This delocalization reduces the availability of the lone pair for protonation, making it less basic than expected.

- **Benzylamine**: Benzylamine does not have any electron-withdrawing groups attached to the nitrogen. The lone pair on nitrogen is not involved in resonance with the aromatic ring, making it more available for donation. Thus, it is expected to be the most basic among the four.

### Step 4: Conclusion
Based on the analysis, benzylamine has the most available lone pair for donation and is not affected by resonance or electron-withdrawing groups. Therefore, the most basic compound among the four options is **benzylamine**.

### Final Answer
The most basic compound is **benzylamine** (option D).

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