The product which is obtained in least amount on the direct nitration of aniline is

Options

A.
B.
C.
D. both (2) and (3)

Answer

To determine the product obtained in the least amount during the direct nitration of aniline, we can follow these steps:

### Step 1: Understand the Nitration Process
Aniline (C6H5NH2) undergoes nitration when treated with a mixture of concentrated nitric acid (HNO3) and concentrated sulfuric acid (H2SO4). This reaction introduces nitro groups (NO2) onto the benzene ring.

**Hint:** Nitration involves adding a nitro group to an aromatic compound.

### Step 2: Identify the Possible Products
The nitration of aniline can yield three possible products:
1. **Para-nitroaniline** (NO2 at the para position relative to the NH2 group)
2. **Meta-nitroaniline** (NO2 at the meta position relative to the NH2 group)
3. **Ortho-nitroaniline** (NO2 at the ortho position relative to the NH2 group)

**Hint:** Identify the positions where the nitro group can attach to the benzene ring.

### Step 3: Consider the Effect of the Amino Group
The amino group (NH2) is an activating group and directs electrophilic substitution to the ortho and para positions. However, under strongly acidic conditions, aniline can be protonated to form anilinium ion (C6H5NH3+), which is meta-directing.

**Hint:** The nature of the substituent (NH2 vs. NH3+) affects the position of the incoming nitro group.

### Step 4: Analyze the Product Ratios
In the nitration of aniline, the expected product ratios are approximately:
- Para-nitroaniline: 51%
- Meta-nitroaniline: 47%
- Ortho-nitroaniline: 2%

From these ratios, it is clear that ortho-nitroaniline is produced in the least amount.

**Hint:** Compare the percentages of each product to identify which one is least abundant.

### Step 5: Conclusion
Thus, the product obtained in the least amount during the direct nitration of aniline is **ortho-nitroaniline**.

**Final Answer:** Ortho-nitroaniline is obtained in the least amount (approximately 2%).