Question

Suitable reaction condition for preparation of Methyl phenyl ether is

• A. PhO- Na+ , MeBr
• B. PhO- Na+ , MeOH
• C. Ph - Br, MeO- Na+
• D. Benzene, MeBr

Hint:

The Williamson Ether Synthesis is a key reaction for preparing ethers. Remem ber that it’s an SN₂ reaction, so it works best with primary alkyl halides (or those with minimal steric hindrance). If a tertiary alkyl halide is used, an elim ination reaction is more likely to occur.

Answer 1

The Correct Option is A

The Williamson ether synthesis involves the reaction of an alkoxide ion with a primary alkyl halide to form an ether:

General Reaction:

\[ R-O^- + R'-X \rightarrow R-O-R' + X^- \]

• \( R-O^- \): Alkoxide ion
• \( R'-X \): Alkyl halide

Reagents for Methyl Phenyl Ether (Ph-O-Me):

• Phenoxide ion (\( \text{PhO}^- \)): Derived from phenol, this acts as the alkoxide.
• Methyl bromide (\( \text{MeBr} \)): A primary alkyl halide used for the methyl group.

Reaction:

\[ \text{PhO}^- \text{Na}^+ + \text{MeBr} \rightarrow \text{Ph-O-Me} + \text{NaBr} \]

Mechanism: The phenoxide ion (\( \text{PhO}^- \)) acts as a nucleophile in an SN2 reaction, attacking the methyl carbon of the methyl bromide. This displaces the bromide ion and forms the ether linkage.

Conclusion:

Methyl phenyl ether (anisole) is prepared by reacting phenoxide ion with methyl bromide in the Williamson ether synthesis.