Question

Which from following compounds is NOT obtained when ethyl chloride reacts with isopropyl chloride in presence of Na and dry ether?

Options

• 2-Methylbutane

• 2,3-Dimethylbutane

• Butane

• Hexane

Answer 1

Hexane

Explanation:

The reaction is known as Wurtz reaction.

\[\ce{\underset{Ethyl bromide}{C2H5Br} + 2Na + \underset{Ethyl bromide}{C2H5Br} \underset{-NaBr}{\overset{dey ether}{->}} \underset{n-Butane}{CH3CH2CH2CH3}}\]

\[\begin{array}{cc}
\phantom{................................}\ce{CH3}\phantom{................................}\ce{CH3}\\
\phantom{............................}|\phantom{......................................}|\\
\ce{\underset{Ethyl bromide}{C2H5Br} + 2Na + \underset{Isopropyl bromide}{BrCHCH3} \underset{-NaBr}{\overset{dry ether}{->}} \underset{2-Methylbutane}{CH3CH2CHCH3}}
\end{array}\]

\[\begin{array}{cc}
\ce{H3C}\phantom{..................................}\ce{CH3}\phantom{..}\\
\backslash\phantom{...............................}/\phantom{..}\\
\ce{CHBr + 2Na + Br CH}\\
/\phantom{...............................}\backslash\phantom{...}\\
\ce{\underset{Isopropyl bromide}{H3C} \phantom{....................}\ce{\underset{Isopropyl bromide}{CH3}}}\phantom{...}
\end{array}\]

\[\begin{array}{cc}
\phantom{...........}\ce{H3C}\phantom{..........}\ce{CH3}\\
\phantom{...........}\backslash\phantom{......}/\\
\ce{\underset{-NaBr}{\overset{dey ether}{->}} CH-}\\
\phantom{..........}/\phantom{.......}\backslash\\
\phantom{..........}\ce{\underset{2,3-Dimethylbutane}{H3C\phantom{.........} CH3}}
\end{array}\]

But n-Hexane cannot be formed.