To identify the primary product of the specified chemical reaction, an examination of the reactants and their involved functional groups is necessary.
The starting material is a benzene ring substituted with a cyano group (\(\text{CN}\)) and a methoxy carbonyl group (\(\text{CO}_2\text{CH}_3\)). The reagents provided are:
(i) \(\text{CH}_3\text{MgBr} \,(\text{excess})\) - A Grignard reagent.
(ii) \(\text{H}_3\text{O}^+\) - Acidic hydrolysis.
Reaction Sequence:
The Grignard reagent, \(\text{CH}_3\text{MgBr}\), will react with the electrophilic carbonyl carbon of the ester group (\(\text{CO}_2\text{CH}_3\)). Subsequent acidic work-up (hydrolysis) will yield an alcohol.
Due to the excess of the Grignard reagent, it will also react twice with the cyano group (\(\text{CN}\)). This double addition, followed by hydrolysis, converts the cyano group into a tertiary alcohol.
Following these transformations, the resultant product is a tertiary alcohol. The original benzene ring remains unchanged, with additional methyl groups attached from the Grignard reagent's participation.
Outcome: The principal product is a tertiary alcohol, formed by the reaction of both the cyano and ester functional groups with an excess of the Grignard reagent, followed by hydrolysis.
