Mechanism of Hoffmann Bromamide Reaction

The Hoffmann Bromamide reaction is a chemical reaction that converts an amide to a primary amine with one fewer carbon atom. The general reaction involves the use of bromine (Br₂) and a strong base like sodium hydroxide (NaOH).

Steps involved in the mechanism:

1. Bromination: The amide reacts with bromine to form an N-bromoamide intermediate.
2. Deprotonation: The strong base (NaOH) deprotonates the N-bromoamide to form a bromoamide anion.
3. Rearrangement: The bromoamide anion undergoes a rearrangement where the carbonyl carbon gets bonded to nitrogen, releasing a bromide ion and forming an isocyanate intermediate.
4. Hydrolysis: The isocyanate intermediate reacts with water to form a carbamic acid, which then decomposes to yield a primary amine and carbon dioxide (CO₂).

The overall reaction can be summarized as:

RCONH₂ + Br₂ + 4NaOH → RNH₂ + Na₂CO₃ + 2NaBr + 2H₂O