

$\begin{array}{*{20}{c}}
{C{H_3}}\\
{|\,\,\,\,\,}\\
{{C_6}{H_5}C{H_2} - C - C{H_2} - C{H_3}}\\
{|\,\,\,\,\,}\\
{Br\,\,\,}
\end{array}$ $\xrightarrow[{{C_2}{H_5}OH}]{{{C_2}{H_5}ONa}}$
$ 3 \mathrm{ROH}+\mathrm{PCl}_3 \rightarrow 3 \mathrm{RCl}+\mathrm{A} $
$ \mathrm{ROH}+\mathrm{PCl}_5 \rightarrow \mathrm{RCl}+\mathrm{HCl}+\mathrm{B}$