Which of the following amides will undergo the Hofmann bromamide degradation reaction to yield a primary amine with one carbon atom less than the starting material?

Solution

1. The Hofmann bromamide degradation requires a primary amide of the form ${\text{RCONH}}_2$.
2. N-substituted amides like ${\text{RCONHR}}^{\prime }$ or ${\text{RCONR}}_2^{\prime }$ do not possess the necessary acidic protons on the nitrogen atom for the formation of the N-bromo intermediate.
3. Benzamide is the only primary amide listed among the choices.
4. Hence the answer is (B).