MHTCET 17 Apr 2026 Shift 1 Paper

Concept:Aryl ester formation via nucleophilic acyl substitution.Explanation:Phenol, written as $\mathrm{Ar}-\mathrm{OH}$, reacts with an acid chloride, $\mathrm{R}-\mathrm{COCl}$, in the presence of pyridine.The oxygen of phenol has a lone pair and attacks the electrophilic carbonyl carbon of the acid chloride.Pyridine acts as a base and removes the $\mathrm{HCl}$ formed during the reaction.This drives the reaction forward to give an ester.The general reaction is:$$\mathrm{Ar}-\mathrm{OH} + \mathrm{R}-\mathrm{COCl} \xrightarrow{\text{Pyridine}} \mathrm{R}-\mathrm{COO}-\mathrm{Ar} + \mathrm{HCl}$$Therefore, $Z$ is an aryl ester having the general structure $\mathrm{R}-\mathrm{COO}-\mathrm{Ar}$.Answer:$Z$ is the aryl ester $\mathrm{R}-\mathrm{COO}-\mathrm{Ar}$, which corresponds to the option showing this ester structure.