Among the following which one does not act as an intermediate in Hofmann rearrangement?
- $\mathrm{RNCO}$
- $R \mathrm{CO} \ddot{\mathrm{N}}$
- $R \mathrm{CON̈HBr}$
- $\mathrm{RNC}$
Solution
(ii) $\mathrm{RCONHBr}+\mathrm{KOH} \rightarrow \mathrm{RNCO}+\mathrm{KBr}+\mathrm{H}_2 \mathrm{O}$
(iii) $\mathrm{RNCO}+2 \mathrm{KOH} \rightarrow \mathrm{RNH}_2+\mathrm{K}_2 \mathrm{CO}_3$
$\mathrm{RCONH}_2+\mathrm{Br}_2+4 \mathrm{KOH} \rightarrow \mathrm{RNH}_2+2 \mathrm{KBr}$
$+\mathrm{K}_2 \mathrm{CO}_3+2 \mathrm{H}_2 \mathrm{O}$Asked in: NEET 2004