Question

Consider following esters and give number of esters which are more reactive than toward basic hydrolysis.

Answer 1

The reactivity of the ester depends upon carbonyl carbon.

EWG in benzene ring increases electrophilicity of $-\underset{\underset{O}{||}}{C}-$ group.

$-R$ and $-I$ groups increase the electrophilicity of the carbonyl carbon.
$-N{O}_2$ , and $-CN$ are $-R$ groups and $-Cl$ is $-I$ group.

$-C{H}_3$ is +R group and decreases the reactivity .

Hence 1, 2, 4, 5 are more reactive than ethyl p-methylbenzoate.