Animated Solution for Chemistry - Organic Chemistry: The major product of the following reaction is

Welcome to a classic organic chemistry puzzle! We are presented with a fascinating molecule: 2-methoxybenzonitrile.

This molecule features an aromatic ring adorned with two distinct functional groups: an electron-donating methoxy group ($-OC{H}_3$) and an electron-withdrawing nitrile group ($-C\equiv N$).

Our mission is to react this molecule with phenylmagnesium bromide ($C_6{H}_{5}MgBr$), a powerful Grignard reagent, followed by an acidic workup ($H_3{O}^{+}$).

Grignard Meets Nitrile

Grignard reagents are essentially sources of nucleophilic carbon atoms (carbanions). In $C_6{H}_{5}MgBr$, the phenyl group acts as a strong nucleophile ($C_6{H}_5^{-}$).

Now, where will this nucleophile attack? The methoxy group is an ether, and ethers are notoriously unreactive towards Grignard reagents. In fact, ethers are used as solvents for these reactions!

The prime target is the nitrile group. The carbon-nitrogen triple bond is highly polarized, making the carbon atom electrophilic.

The phenyl anion attacks the electrophilic carbon of the nitrile group.

This forces the pi electrons of the triple bond to shift onto the nitrogen atom. The result is the formation of an imine salt intermediate: $Ar-C(C_6{H}_5)=NMgBr$.

Throughout this dramatic attack, the methoxy group at the ortho position sits quietly, completely unaffected by the chaos.

Acid Hydrolysis

The reaction doesn't stop at the imine salt. The second step involves adding aqueous acid ($H_3{O}^{+}$).

Acid hydrolysis of an imine salt is a standard procedure to convert the carbon-nitrogen double bond into a carbon-oxygen double bond.

The nitrogen atom is protonated and eventually leaves as ammonia ($N{H}_3$), while an oxygen atom takes its place.

This elegant transformation yields our final major product: 2-methoxybenzophenone.

The methoxy group remains at the ortho position relative to the newly formed ketone group. Comparing this to our options, it perfectly matches Option (d).

Always remember this golden rule: Grignard reagents react with nitriles to form ketones, whereas they react with esters to form tertiary alcohols. Keep this distinction sharp, and you'll master these conversions!