The reaction used for the synthesis of ether is

This reaction is general methods of preparation from alkyl halides

According to this question the reaction which is used for the synthesis of ether is undergoes in ${\mathrm{S}}_{{\mathrm{N}}_2}$ reaction

It is formed from the reaction of alkyl halides and sodium ethoxide

$\mathrm{R}-\mathrm{X} + {\mathrm{C}}_2{\mathrm{H}}_5{\mathrm{O}}^{-} {\mathrm{Na}}^{+} \stackrel{\mathrm{ester}}{\to } \mathrm{R} -\mathrm{O}-{\mathrm{C}}_2{\mathrm{H}}_5$