In the following of acetamide derivative the reactivity of `NH_(3)` is greatest towards .

Options

A. acetic anhydride
B. ethyl acetate
C. acetyl chloride
D. acetic acid

Answer

To solve the question regarding the reactivity of ammonia (NH₃) towards acetamide derivatives, we will analyze the reactivity of NH₃ with four different compounds: acetic anhydride, ethyl acetate, acetyl chloride, and acetic acid.

### Step-by-Step Solution:

1. **Identify the Compounds**: The compounds in question are:
- Acetic Anhydride (CH₃CO)₂O
- Ethyl Acetate (CH₃COOCH₂CH₃)
- Acetyl Chloride (CH₃COCl)
- Acetic Acid (CH₃COOH)

2. **Understand the Role of NH₃**: Ammonia (NH₃) acts as a nucleophile due to the presence of a lone pair of electrons on the nitrogen atom. Nucleophiles are attracted to positively charged or electron-deficient centers in molecules.

3. **Analyze Each Compound**:
- **Acetic Anhydride**: The carbonyl carbon in acetic anhydride has some positive character due to the electronegativity of oxygen. However, the presence of two carbonyl groups can lead to resonance stabilization, which reduces the electrophilicity of the carbonyl carbon.

- **Ethyl Acetate**: Similar to acetic anhydride, the carbonyl carbon in ethyl acetate is also stabilized by resonance due to the lone pair on the oxygen atom. This reduces the electrophilicity of the carbonyl carbon, making it less reactive towards nucleophiles.

- **Acetyl Chloride**: The carbonyl carbon in acetyl chloride is more electrophilic because chlorine is an electron-withdrawing group. This increases the positive character of the carbonyl carbon, making it more reactive towards nucleophiles like NH₃.

- **Acetic Acid**: The carbonyl carbon in acetic acid is also stabilized by resonance from the hydroxyl group, which decreases its electrophilicity. Thus, it is less reactive towards nucleophiles compared to acetyl chloride.

4. **Determine the Greatest Reactivity**: Among the four compounds, acetyl chloride exhibits the highest electrophilicity due to the electron-withdrawing effect of chlorine. Therefore, NH₃ will be most reactive towards acetyl chloride.

### Final Answer:
The reactivity of NH₃ is greatest towards **acetyl chloride (C)**.