Question

Which one of the following reactions is NOT possible?

• A.
• B.
• C.
• D.

Answer 1

The Correct Option is B

Step 1: Analyze each reaction
1. Reaction (1):  
The reaction involves the cleavage of the ether bond (\(\text{C} - \text{OCH}_3\)) by \(\text{HBr}\), producing phenol (\(\text{C}_6\text{H}_5 - \text{OH}\)). This reaction is possible due to the nucleophilic substitution mechanism.
2. Reaction (2):
The reaction involves the conversion of phenol (\(\text{C}_6\text{H}_5 - \text{OH}\)) to chlorobenzene (\(\text{C}_6\text{H}_5 - \text{Cl}\)) by \(\text{HCl}\). However, this reaction is \textbf{NOT} possible because the hydroxyl group in phenol is directly attached to the benzene ring, and it does not undergo nucleophilic substitution to form \(\text{C}_6\text{H}_5 - \text{Cl}\). The lone pair on oxygen in phenol makes the \(-\text{OH}\) group resistant to substitution by \(\text{HCl}\).
3. Reaction (3): 
The reaction involves the hydrolysis of chlorobenzene (\(\text{C}_6\text{H}_5 - \text{Cl}\)) under high temperature and pressure in the presence of \(\text{NaOH}\). This reaction is possible via nucleophilic aromatic substitution, producing phenol (\(\text{C}_6\text{H}_5 - \text{OH}\)).
4. Reaction (4):
The reaction involves the electrophilic substitution of anisole (\(\text{C}_6\text{H}_5 - \text{OCH}_3\)) with chlorine in the presence of \(\text{AlCl}_3\). This reaction is possible, producing a mixture of ortho and para substituted products.
Step 2: Conclusion
Among the given reactions, only Reaction (2) is not possible because phenol does not undergo nucleophilic substitution with \(\text{HCl}\) to form chlorobenzene.
Final Answer: (2).