The reaction(s) leading to the formation of 1, 3, 5 -trimethylbenzene is (are)

Options

A.
B.
C.
D.

Answer

To determine the reactions that lead to the formation of 1,3,5-trimethylbenzene, we will analyze the provided options step by step.

### Step-by-Step Solution:

1. **Understanding the Structure of 1,3,5-Trimethylbenzene**:
- The molecular structure of 1,3,5-trimethylbenzene consists of a benzene ring with three methyl (CH₃) groups attached at the 1st, 3rd, and 5th positions.

2. **Analyzing Option A**:
- **Reagents**: Acetone treated with concentrated H₂SO₄ and heat.
- **Reaction**: Three moles of acetone (CH₃COCH₃) undergo dehydration in the presence of concentrated sulfuric acid. This leads to the formation of benzene with three methyl groups at the specified positions.
- **Conclusion**: This reaction successfully yields 1,3,5-trimethylbenzene. **(Correct)**

3. **Analyzing Option B**:
- **Reagents**: Acetylene heated in an iron tube at 873 K.
- **Reaction**: Three moles of acetylene (C₂H₂) undergo coupling reactions when heated, leading to the formation of 1,3,5-trimethylbenzene.
- **Conclusion**: This reaction also yields 1,3,5-trimethylbenzene. **(Correct)**

4. **Analyzing Option C**:
- **Reagents**: A compound with acetyl groups at the 1st, 3rd, and 5th positions treated with Br₂ and NaOH, followed by H₃O⁺ and soda lime.
- **Reaction**: The haloform reaction occurs, where the acetyl groups are converted, and soda lime treatment removes CO₂. However, this does not lead to the formation of 1,3,5-trimethylbenzene.
- **Conclusion**: This reaction does not yield the desired product. **(Incorrect)**

5. **Analyzing Option D**:
- **Reagents**: A compound with aldehyde groups at the 1st, 3rd, and 5th positions treated with Zn/Hg and HCl.
- **Reaction**: This is a Clemmensen reduction, which converts the aldehyde groups (CHO) into methyl groups (CH₃).
- **Conclusion**: This reaction yields 1,3,5-trimethylbenzene. **(Correct)**

### Final Conclusion:
The reactions that lead to the formation of 1,3,5-trimethylbenzene are found in options A, B, and D. Therefore, the correct answers are A, B, and D.