Question

Write Hofmann’s bromamide reaction.

Answer 1

The Hofmann bromamide reaction involves the reaction of amide, bromine, and sodium hydroxide which gives amine and other products. One needs to write a balanced reaction equation for the reaction with all the formed products.

Complete answer:

1. First of all let’s discuss the Hofmann bromamide reaction which is the major reaction used for the synthesis of primary amines.
2. Now let us see the general reaction of the Hofmann bromamide reaction as below,
   The balanced general reaction,
   $RCON{H_2} + B{r_2} + 4NaOH\xrightarrow{\Delta }R - N{H_2} + N{a_2}C{O_3} + 2NaBr + 2{H_2}O$
   In the above reaction when an amide reacts with the bromine and sodium hydroxide which yields the major product as primary amine, sodium carbonate, two moles of sodium bromide, and two moles of water.
3. Now let us see an example for the reaction as below,
   $C{H_2}CON{H_2} + Br + 4NaOH\xrightarrow{\Delta }C{H_3}N{H_2} + 2NaBr + N{a_2}C{O_3} + 2{H_2}O$
   In the above reaction, the acetamide reacts with the bromine and the sodium hydroxide in the presence of heat which gives the product the Methanamine as the major product with other products such as two moles of sodium bromide, sodium carbonate, and two molecules of water.
4. This reaction can also be called the reaction of Hofmann degradation of amide.
5. The heat or thermal conditions that are used in this reaction causes the explosion of carbon dioxide gas and also the quenching of the ammonium cation which is formed during the reaction to form the required amine product.

Note:
In the reaction of Hoffmann bromamide there is a formation of an amine with one less carbon than an amide. This method produces the primary aliphatic and aromatic amines. This method is also used for the preparation of aniline.