See image — Reaction Mechanism Chemistry Question

💡 Solution & Explanation

Concept: Grignard reagents are highly reactive organometallic compounds that react with any electrophilic or protic functional group. The solvent used to dissolve the substrate (ethyl benzoate) must be completely inert toward the Grignard reagent (PhMgBr). Step 1 - Eliminate option (c) absolute alcohol: Alcohols are protic solvents. PhMgBr would immediately react with any O-H bond (ROMgBr + PhH), destroying the Grignard reagent. This is completely incompatible. Step 2 - Eliminate option (a) acetone: Acetone contains a ketone carbonyl group (C=O). PhMgBr would react with acetone via nucleophilic addition to give a tertiary alcohol adduct. The solvent itself would be consumed, destroying the Grignard reagent. Step 3 - Eliminate option (b) ethyl acetate: Ethyl acetate is an ester and contains a reactive carbonyl group. PhMgBr would react with ethyl acetate (first to give a ketone intermediate, then a tertiary alcohol), so it cannot serve as an inert solvent. Step 4 - Evaluate option (d) benzene: Benzene is a non-polar, aprotic hydrocarbon solvent with no reactive functional groups (no active hydrogen, no electrophilic carbonyl). PhMgBr does not react with benzene under normal conditions. Ethyl benzoate can be dissolved in benzene, and the Grignard reaction can proceed without the solvent interfering. Benzene (or toluene) is indeed used as a co-solvent in Grignard reactions when needed. Therefore, the correct answer is D.