Question

Why pmethoxybenzyl bromide reacts faster with p-nitrobenzyle bromide with sodium ethoxide to form an ether product?

Answer 1

✔✅ Methoxy group is an electron releasing group which stabilises the intermediate carbocation. Formation of carbocation is the rate determining step, more the stability of carbocation, faster is the reaction. Hence, p-methoxybenzyl bromide reacts faster than p-nitrobenzyl bromide with ethanol to form ether.

Answer 2

p-methoxy benzyl bromide reacts faster than p-nitrobenzyl bromide because NO2group at p-position is an electron withdrawing, the electron density reduced at o- and p-position. Nitro group is resonance hybrid so it produces steric hindrance.
So p-methoxy benzyl bromide reacts faster than p-nitro benzyl bromide. The p-methoxy is a primary substituted.