Question

The heating of phenyl-methyl ethers with HI produces.

• A. Ethyl chlorides
• B. Iodobenzene
• C. Phenol
• D. Benzene

Answer 1

The Correct Option is C

The question asks about the product formed when phenyl-methyl ethers react with hydrogen iodide (HI). This is an example of a nucleophilic substitution reaction where the ether is cleaved by HI. Let's break down the reaction step-by-step to find out why phenol is produced.

1. Reaction Mechanism:
   • Phenyl-methyl ether has the structure {\small \text{C}_6\text{H}_5\text{OCH}_3}.
   • When treated with HI, the ether bond is cleaved. The reaction proceeds through a bimolecular nucleophilic substitution mechanism (S_N2).
   • The oxygen in the ether takes up a proton from HI, forming water and leaving a methyl cation (CH₃⁺).
   • The iodide ion (I^-) from HI attacks the methyl cation, forming methyl iodide (CH₃I).
   • The phenyl part of the molecule (C₆H₅) becomes phenol due to the cleavage of the ether bond.
2. Products of the Reaction:
   • The main organic products of this reaction are phenol and methyl iodide.

Therefore, the reaction can be summarized as follows:

\text{C}_6\text{H}_5\text{OCH}_3 + \text{HI} \rightarrow \text{C}_6\text{H}_5\text{OH} + \text{CH}_3\text{I}

Based on the mechanism and the products formed, we can see that the correct answer is Phenol. Let's rule out the other options:

• Ethyl chlorides: This does not form in this reaction because there are no ethyl groups involved and HI is used, not a chlorinating agent.
• Iodobenzene: Though phenyl iodide (iodobenzene) might appear plausible, it doesn't form because the reaction specifically cleaves at the ether linkage to yield phenol.
• Benzene: Benzene cannot be a product because the ether linkage specifically cleaves to give phenol, not benzene.

In conclusion, the heating of phenyl-methyl ethers with HI results in the formation of Phenol.