Which of the following electrophilic aromatic substitution is expected to show a maderate `(K_(H))/(K_(D))` isotope effect?

Options

A. Sulphonation
B. Nitration
C. Acylation
D. Alkylation

Answer

1

Explanation

Since `K_(2)approxK_(-1)` the overall rate is affected by `K_(2)` the loss of `D^(+)` from the deuterated `sigma` complex has a greater activation energy than the comparable loss of `H^(+)` and is slower. Thus, sulphonation exhibits a moderate primary isotope effect.