The structure of a specific aromatic ketone is shown below. Which...

The given compound is propiophenone, $Ph-CO-CH_2CH_3$.

(A) Benzene reacts with propanoyl chloride in the presence of anhydrous $AlCl_3$ via Friedel-Crafts acylation to form propiophenone. This is a correct method to synthesize the compound.

(B) Benzonitrile ($Ph-CN$) reacts with ethylmagnesium bromide ($CH_3CH_2MgBr$) to form an imine salt, which upon acid hydrolysis yields propiophenone. This is a correct method.

(C) Benzoyl chloride ($Ph-COCl$) reacts with diethylcadmium ($(CH_3CH_2)_2Cd$) to form propiophenone. Dialkylcadmium reagents are less reactive and stop at the ketone stage without reacting further. This is a correct method.

(D) Benzoyl chloride reacts with excess ethylmagnesium bromide to initially form propiophenone. However, Grignard reagents are highly reactive, and the excess reagent will react further with the formed ketone to produce a tertiary alcohol (3-phenylpentan-3-ol) after acid hydrolysis. Therefore, the ketone is not obtained as the major product.

Thus, the reaction sequence in option (D) is the incorrect method for synthesizing the given ketone.

Answer: Reaction of benzoyl chloride with excess ethylmagnesium bromide, followed by acid hydrolysis