Which of the following reactions are feasible ?

Options

A.
B.
C.
D.

Explanation

To determine which of the given reactions are feasible, we will analyze each reaction step by step.

### Step 1: Analyze the First Reaction
- **Reaction**: Chlorobenzene + K, NH2, NH3
- **Mechanism**: Nucleophilic substitution via the benzyne mechanism (Elimination-Addition mechanism).
- **Key Point**: For the benzyne mechanism to occur, there must be a hydrogen atom at the ortho position to the halogen (Cl in this case).
- **Conclusion**: Chlorobenzene has hydrogen atoms at the ortho position, allowing for the elimination of Cl and subsequent addition of NH2.
- **Feasibility**: **Feasible**

### Step 2: Analyze the Second Reaction
- **Reaction**: Chlorobenzene with CH3 groups (Me) and K, NH2, NH3
- **Mechanism**: Similar to the first reaction, we will assess the presence of hydrogen atoms at the ortho position.
- **Key Point**: The presence of hydrogen at the ortho position is crucial for the reaction to proceed.
- **Conclusion**: Chlorobenzene has hydrogen atoms at the ortho position, allowing for the elimination of Cl and the addition of NH2.
- **Feasibility**: **Feasible**

### Step 3: Analyze the Third Reaction
- **Reaction**: Bromobenzene with EtO and Et
- **Mechanism**: We need to check for the presence of hydrogen atoms at the ortho position.
- **Key Point**: If there are no hydrogen atoms at the ortho position, the nucleophilic substitution cannot occur.
- **Conclusion**: In this case, there are no hydrogen atoms at the ortho position to facilitate the reaction.
- **Feasibility**: **Not feasible**

### Step 4: Analyze the Fourth Reaction
- **Reaction**: Chlorobenzene with Me groups (Me) and K, NH2, NH3
- **Mechanism**: Again, we will check for hydrogen atoms at the ortho position.
- **Key Point**: The presence of hydrogen at the ortho position is essential for the reaction to proceed.
- **Conclusion**: Similar to the third reaction, there are no hydrogen atoms at the ortho position to facilitate the nucleophilic substitution.
- **Feasibility**: **Not feasible**

### Final Conclusion
The feasible reactions are:
- **First Reaction**: Feasible
- **Second Reaction**: Feasible
- **Third Reaction**: Not feasible
- **Fourth Reaction**: Not feasible

Thus, the correct answers are **1 and 2**.

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