Which of the following is most reactive towards nucleophilic substritution reaction?

Options

A. Ethyl acetate
B. Acetic anhydride
C. Acetamide
D. Acetyl chloride

Answer

To determine which of the given compounds is most reactive towards nucleophilic substitution reactions, we will analyze the reactivity of each compound based on the nature of their leaving groups. The compounds in question are ethyl acetate, acetic anhydride, acetamide, and acetyl chloride.

### Step-by-Step Solution:

1. **Identify the Compounds:**
- Ethyl acetate: CH3COOCH2CH3
- Acetic anhydride: (CH3CO)2O
- Acetamide: CH3CONH2
- Acetyl chloride: CH3COCl

2. **Understand Nucleophilic Substitution:**
Nucleophilic substitution involves a nucleophile attacking the electrophilic carbon atom, leading to the displacement of a leaving group. The reactivity of the compound in nucleophilic substitution reactions is influenced by the ability of the leaving group to depart.

3. **Identify the Leaving Groups:**
- In ethyl acetate, the leaving group is the ethoxy group (OCH2CH3).
- In acetic anhydride, the leaving group is the acyl group (OCOCH3).
- In acetamide, the leaving group is the amine group (NH2).
- In acetyl chloride, the leaving group is the chloride ion (Cl).

4. **Evaluate the Leaving Group Ability:**
The ability of a leaving group to depart is inversely related to its basicity. A weaker base is a better leaving group. The order of basicity (and thus leaving group ability) for the relevant groups is as follows:
- Cl⁻ (from acetyl chloride) is a weak base and thus a very good leaving group.
- OCOCH3 (from acetic anhydride) is a moderate leaving group.
- OCH2CH3 (from ethyl acetate) is a weaker leaving group than acetic anhydride but stronger than Cl⁻.
- NH2⁻ (from acetamide) is a strong base and thus a poor leaving group.

5. **Rank the Compounds:**
Based on the leaving group ability:
- Acetyl chloride (Cl⁻) > Acetic anhydride (OCOCH3) > Ethyl acetate (OCH2CH3) > Acetamide (NH2)
Thus, acetyl chloride has the best leaving group and is therefore the most reactive towards nucleophilic substitution.

6. **Conclusion:**
Acetyl chloride is the most reactive compound towards nucleophilic substitution among the given options.

### Final Answer:
**Acetyl chloride is the most reactive towards nucleophilic substitution.**