In the Hofmann bromamide degradation reaction, the number of moles of NaOH and $\mathrm{Br}_{2}$ used per mole of amine produced are:

(C) Four moles of NaOH and one mole of $\mathrm{Br}_{2}$

(A) Four moles of NaOH and two moles of $\mathrm{Br}_{2}$.

(B) Two moles of NaOH and two moles of $\mathrm{Br}_{2}$

(D) One mole of NaOH and one mole of $\mathrm{Br}_{2}$

JEE Main · 2016 · 03 Apr 2016 · Offline · Aldehydes Ketones and Carboxylic Acids

In the Hofmann bromamide degradation reaction, the number of moles of NaOH and

Br_{2}

used per mole of amine produced are:

Answer: (C)

In the Hofmann bromamide reaction a primary amide is cut down to an amine with one fewer carbon. Forming the N-bromoamide uses one

Br X_{2}

and two

NaOH

, and hydrolysing the isocyanate that follows consumes two more

NaOH

, giving the overall balance

RCONH X_{2} + Br X_{2} + 4 NaOH RNH X_{2} + Na X_{2} CO X_{3} + 2 NaBr + 2 H X_{2} O

. Each mole of amine therefore needs four moles of

NaOH

and one mole of

Br X_{2}

JEE Main · 2016 · 03 Apr 2016 · Offline · Single correct option