Target Exam

CUET

Subject

Chemistry

Chapter

Organic: Alcohols, Phenols and Ethers

Question:

Anisole on heating with concentrated HI gives

Options:

Iodobenzene

Iodobenzene and methanol

Phenol and methyl iodide

Phenol and methanol

Correct Answer:

Phenol and methyl iodide

Explanation:

The correct answer is Option (3) → Phenol and methyl iodide

Anisole ($C_6H_5-O-CH_3$) is an aryl-alkyl ether. When heated with concentrated HI, cleavage of the ether bond occurs at the alkyl-oxygen bond (not at the aryl-oxygen bond) because:

  • The $C_6H_5-O$ bond has partial double-bond character due to resonance, making it strong and difficult to break.
  • The $CH_3-O$ bond is weaker and undergoes nucleophilic substitution by $I^-$.

Reaction:

$C_6H_5-O-CH_3 + HI→ C_6H_5OH + CH_3I$

Thus, the products are phenol ($C_6H_5OH$) and methyl iodide ($CH_3I$).

Hence, the correct answer is phenol and methyl iodide.