Ethoxythane can be produced from ethanol by dehydration. However, great care must be taken here. This is because alkanols undergo two forms of dehydration: Partial dehydration and total dehydration.
In partial dehydration, two molecules of an alkanol lose one molecule of \(\mathrm{H}_2 \mathrm{O}\) to give an alkoxyalkane. This is attained when the alkanol is in excess and the temperature is around \(145^{\circ} \mathrm{C}\) (any temp. below \(170^{\circ} \mathrm{C}\) ).
In total dehydration, one molecule of an alkanol loses one molecule of water to produce an alkene. This requires excess conC. \(\mathrm{H}_2 \mathrm{SO}_4\) and a temperature around \(180^{\circ} \mathrm{C}\) (any temp. above \(\left.180^{\circ} \mathrm{C}\right)\)
\(\mathrm{CH}_3 \mathrm{CH}_2 \mathrm{OH} \frac{\mathrm{H}_2 \mathrm{SO}_4}{180^{\circ} \mathrm{C}} \mathrm{CH}_2=\mathrm{CH}_2+\mathrm{H}_2 \mathrm{O}\) \(2 \mathrm{CH}_3 \mathrm{CH}_2 \mathrm{OH} \underset{2 \mathrm{H}_2 \mathrm{SO}_4}{145^{\circ} \mathrm{C}} \mathrm{C}_2 \mathrm{H}_5-\mathrm{O}-\mathrm{C}_2 \mathrm{H}_5+\mathrm{H}_2 \mathrm{O}\)