14.27 : تحويل النتريلات إلى كيتونات: تفاعل جرينارد

Nitriles can be converted to ketones in the presence of organomagnesium halides, known as Grignard reagents.

The reaction proceeds via a nucleophilic acyl substitution, introducing a new carbon–carbon bond.

Notably, the alkyl–magnesium bond in the Grignard reagent is highly polar. As a result, the alkyl carbon develops a carbanionic character and acts as a nucleophile in the reaction.

The first step of the mechanism begins with a nucleophilic attack by the Grignard reagent at the nitrile carbon, forming an anion.

The second step involves protonation of the anion with an aqueous acid to form an imine as an intermediate.

Since the imine intermediate is not isolated, it enters the next step, where the imine is hydrolyzed under acidic conditions to yield ketone as the final product.