Acetanilide when treated with bromine in acetic acid gives:

Options

A. o - Bromoacetanilide
B. N - Bromoacetanilide
C. p - Bromoacetanilide
D. m - Bromoacetanilide

Answer

To solve the question of what Acetanilide gives when treated with bromine in acetic acid, we can follow these steps:

### Step 1: Identify the Structure of Acetanilide
Acetanilide is an amide derivative of aniline. Its structure can be represented as follows:
- The molecular formula is C8H9NO.
- The structure includes an aniline part (C6H5NH) and an acetyl group (COCH3).

### Step 2: Understand the Reaction Conditions
The reaction takes place in the presence of bromine (Br2) and acetic acid (CH3COOH). Acetic acid serves as a solvent and can also help in stabilizing the intermediate formed during the reaction.

### Step 3: Analyze the Activating Group
The acetyl group (COCH3) attached to the nitrogen atom is an electron-withdrawing group through resonance. However, it also has some electron-donating character due to the lone pair on the nitrogen atom. This means that the nitrogen can donate electron density to the aromatic ring, particularly at the ortho and para positions.

### Step 4: Determine the Sites of Electrophilic Attack
When bromine (an electrophile) approaches the aromatic ring of acetanilide, it can attack the ortho or para positions. However, the ortho position has steric hindrance due to the presence of the acetyl group, making the para position more favorable for the electrophilic substitution.

### Step 5: Predict the Product
Since the para position is less hindered and more favorable for bromination, the bromine will attach to the para position of the aromatic ring. The product formed will be para-bromoacetanilide.

### Step 6: Write the Final Reaction
The overall reaction can be summarized as:
\[ \text{Acetanilide} + \text{Br}_2 \xrightarrow{\text{Acetic Acid}} \text{para-Bromoacetanilide} + \text{HBr} \]

### Final Answer
Acetanilide when treated with bromine in acetic acid gives para-bromoacetanilide.

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