Question

Write a mechanism for the bromination of acetanilide with bromine in acetic acid. Be as complete as possible and include all relevant resonance structures.

Answer 1

Answer:

See figure 1 and 2

Explanation:

In this case, we can start with the general reaction. Acetanilide with bromine in acetic acid we will produce p-bromo-acetanilide (See figure 1).

In the reaction mechanism, we have as first step the attack of the double bond in the benzene ring to one of the Br atoms in bromine ($Br_2$) and a positive carbon will be produced in benzene. This positive charge can be moved inside of the benzne ring producing the resonance structures A, B and D. Resonance structure C is produced when a double bond is generating between the "N" atom and the carbon in the benzene ring.

The final step in the mechanism is when we remove the "H" atom in structure A to produce again the double bond.

See figure 2

I hope it helps!