Question

How ketones are prepared from nitriles?

Answer 1

Ketones are made by reacting nitriles with Grignard reagent in dry ether as a solvent, then acid hydrolyzing them.

\[\begin{array}{cc}
\phantom{}\ce{\underset{(Ehtanenitrile)}{H3C - C ≡ N} + H3CMgCl ->[dry ether] CH3 - \underset{|}{C} = NMgCl ->[H3O^⊕] \underset{(Acetone)}{CH3 - CO - CH3} + NH3 + Mg(Cl)OH}\\
\ce{H3C}\phantom{................}
\end{array}\] 

\[\begin{array}{cc}
\phantom{}\ce{ \underset{(Benzonitrile)}{C6H5 - C ≡ N} + C6H5 - MgBr ->[dry ether] C6H5 - \underset{|}{C} = NMgBr ->[H3O^⊕] \underset{(Benzophenone)}{C6H5 - CO - C6H5} + NH3 + Mg(Br)OH}\\
\ce{C6H5}\phantom{.......}
\end{array}\]