Question

why p-methoxy benzyl bromide reacts faster than p-nitrobenzyl bromide with ethanol to form an ether product.

Answer 1

In the corresponding reaction of Ethanol with P- methoxybenzylbromide and P-nitrobenzylbromide, the basic difference is in the groups present at Para position and that is -OCH₃ (methoxy ) and nitro NO₂ groups.

we know that -OMe group is electron donating group so when it is attacked by the alcohol this group stabilizes the intermediate carbocation while the nitro group are electron withdrawing groups which snatches electrons from the system and makes it more deficient and so it becomes difficult to stabilize the carboctaion formed during the reaction.

Thus, the P- methoxybenzylbromide reacts faster with the ethanol to produce ether.