Q11P - Organic Chemistry (Mcmurry)

Question

How might you prepare 2-phenylethanol from benzyl bromide? More than one step is needed.

Step-by-Step Solution

Answer

The final product, 2-phenylethanol is prepared from benzyl bromide by following method.

Step1: Conversion of benzyl bromide into 2-phenylacetic acid.

In the first step, benzyl bromide reacts with $\mathit{N}\mathit{a}\mathit{C}\mathit{N}$ which acts as a nucleophile to produce benzylnitrile via a second order nucleophilic substitution mechanism.

In the second step, the hydrolysis of the newly produced benzylnitrilein the presence of aqueous acid $\left({\mathrm{H}}_3{\mathrm{O}}^{+}\right)$ to form 2-phenylacetic acid as shown below.

Step 2: Conversion of 2-phenylacetic acid into 2-phenylethanol

In the third step, 2-phenylacetic acid is converted to 2-phneylethnaol by using the strong reducing agent, ${\mathrm{LiAIH}}_4$. This above reaction is represented as follows: