See image — GOC and Organic Chemistry Basics Chemistry Question

💡 Solution & Explanation

# Reaction of Anisole with HBr **Step 1: Identify the reaction type** This is a cleavage reaction of an aryl ether ($Ar$-$O$-$CH_3$) with hydrohalic acid ($HBr$). The $C$-$O$ bond of the methoxy group breaks under acidic conditions. **Step 2: Determine the cleavage mechanism** In aryl methyl ethers, $HBr$ cleaves the alkyl-oxygen bond (not the aryl-oxygen bond) because: - The aryl-$O$ bond is very strong (resonance stabilized by the aromatic ring) - The alkyl-$O$ bond is weaker and preferentially breaks - This follows Fission's rule: the weaker bond breaks **Step 3: Write the reaction products** $$\text{Anisole} + HBr \rightarrow \text{Phenol} + CH_3Br$$ The $O$-$CH_3$ group is replaced by $O$-$H$, forming **phenol ($C_6H_5OH$)** and **methyl bromide ($CH_3Br$)**. **Step 4: Evaluate the options** - **(A)** Incorrect: Predicts aromatic bromination (wrong mechanism) - **(B)** Incorrect: Predicts aromatic substitution instead of ether cleavage - **(C)** Incorrect: Produces methanol instead of methyl bromide - **(D)** **Correct:** Ether cleavage gives phenol and $CH_3Br$ ✓ **Answer: (D) Phenol and $CH_3Br$**