Question

Write the chemical equations involved in the following reactions:
(i) Hoffmann-bromamide degradation reaction.
(ii) Carbylamine reaction.

Answer 1

(i) Hoffmann-bromamide degradation reaction:
When an amide is treated with bromine and aqueous or alcoholic sodium hydroxide, it gives a primary amine.
In this reaction, the amine obtained contains one C atom less than amide.
$Ph-CON{H}_2+B{r}_2+4NaOH\to Ph-N{H}_2+N{a}_{2}C{O}_3+2NaBr+2H_{2}O$
(ii) Carbylamine reaction:
Aliphatic or aromatic primary amines on heating with chloroform and alcoholic potassium hydroxide gives foul smelling alkyl isocyanides or carbylamines. Secondary or tertiary amines do not give this test.
$Ph-N{H}_2+CHC{l}_3+3KOH\stackrel{\Delta }{\to }Ph-NC+3KCl+3H_{2}O$