Question

\(R-CONH_{2}+Br_{2}+4NaOH \rightarrow R-NH_{2}+Na_{2}CO_{3}+2NaBr+2H_{2}O\); this reaction is:

• A. Hinsberg reaction
• B. Carbylamine reaction
• C. Sandmeyer reaction
• D. Hofmann bromamide reaction

Hint:

Remember the characteristic reaction: \[ \boxed{ RCONH_2 \xrightarrow[\mathrm{NaOH}]{Br_2} RNH_2 } \] The amine formed contains \[ \boxed{\text{one carbon atom less}} \] than the corresponding amide.

Answer 1

The Correct Option is D

This is the Hofmann bromamide degradation, which converts a primary amide $R-CONH_2$ to a primary amine $R-NH_2$ with one fewer carbon. Bromine and alkali generate an isocyanate intermediate via 1,2-migration of the R group from carbon to nitrogen, and the carbonyl carbon is expelled as sodium carbonate.