Question

How acetone is prepared from nitriles using Grignard reagent?

Answer 1

Acetone is prepared from n itriles using Grignard reagent in dry ether as solvent followed by acid hydrolysis.

$$\begin{array}{c}\underset{(\mathrm{Ethane}\mathrm{nitrile})}{\mathrm{H}{\phantom{A}}_3\mathrm{C}-\mathrm{CN}}+\underset{(\mathrm{Grinard}\mathrm{reagent})}{\mathrm{H}{\phantom{A}}_3\mathrm{C}-\mathrm{Mg}-\mathrm{Cl}}\underset{\mathrm{ether}}{\overset{\mathrm{dry}}{\to }}\mathrm{CH}{\phantom{A}}_3-\mathrm{C}=\mathrm{NMgCl}\\ \phantom{..............................}|\\ \phantom{................................}\underset{(\mathrm{Complex})}{\mathrm{CH}{\phantom{A}}_3}\end{array}$$

$$\begin{array}{c}\phantom{...............................................}\mathrm{Cl}\\ \phantom{............................................}/\\ \mathrm{CH}{\phantom{A}}_3-\mathrm{C}=\mathrm{NMgCl}\underset{\mathrm{Hydrolysis}}{\overset{\mathrm{H}{\phantom{A}}_3\mathrm{O}{\phantom{A}}^{\oplus }}{\to }}\mathrm{CH}{\phantom{A}}_3-\mathrm{C}-\mathrm{CH}{\phantom{A}}_3+\mathrm{Mg}+\mathrm{NH}{\phantom{A}}_3\\ \phantom{....}|\phantom{...........................}||\phantom{...........}\mathrm{\setminus }\phantom{.....}\\ \phantom{..........}\mathrm{CH}{\phantom{A}}_3\phantom{......................}\underset{(\mathrm{Acetone})}{\mathrm{O}}\phantom{........}\mathrm{OH}\phantom{............}\end{array}$$