Practicing Success

Target Exam

CUET

Subject

Chemistry

Chapter

Organic: Haloalkanes and Haloarenes

Question:

What will be the product of the following reaction?

Options:

\(C_6H_5COC_2H_5\)

\(C_6H_5OC_2H_5\)

\(C_6H_5OC_2H_4Cl\)

\(C_2H_5OC_2H_5\)

Correct Answer:

\(C_6H_5OC_2H_5\)

Explanation:

The correct answer is option 2. \(C_6H_5OC_2H_5\).

The reaction between sodium phenoxide and ethyl chloride is a well-known example of Williamson’s reaction which involves a substitution bimolecular mechanism to produce the corresponding ethers.

The alkyl group attached to the halogen breaks apart and forms a bond with the oxygen of the phenoxide group to give ethyl phenyl ether. The remaining sodium ions and chloride ions react with each other to form sodium chloride as a byproduct.

The reaction can be initiated by forming phenoxide ions from phenol that can be used to react with alkyl halides.

Since, the mechanism is \(S_N2\) in nature, the alkyl halide needs to be a primary alkyl halide as the reactivity decreases with increasing substitutions. A secondary or tertiary alkyl halide fails to produce an ether by substitution mechanism and elimination is preferred over a substitution reaction. Both protic or aprotic solvents can be used for this type of ether synthesis.

The reaction can be written as follows: