Question

An aromatic compound ‘A’ on treatment with aqueous ammonia and heating

forms a compound ‘B’ which on heating with Br2 and KOH forms a compound ‘C’

of molecular formula C6H7N. Write the structures and IUPAC names of the

Compounds A, B, C. Also write the reactions involved. ​

Answer 1

Explanation:

The aromatic compound A is benzoic acid C 6 H 5COOH.

On treatment with aqueous ammonia and heating forms compound B, which is benzamide C 6 H 5 CONH 2 .

Benzamide on heating with bromine and KOH forms a compound C of molecular formula C 6 H 7

N, which is aniline C 6 H 5 NH 2

. The reaction is called Hoffmann bromamide degradation.

Answer 2

Answer:

It is given that compound 'C' having the molecular formula, C6H7N is formed by heating compound 'B' with Br2 and KOH. This is a Hoffmann bromamide degradation reaction. Therefore, compound 'B' is an amide and compound 'C' is an amine.

The only amine having the molecular formula, C6H7N is aniline, (C6H5NH2).

Therefore, compound 'B' (from which 'C' is formed) must be benzamide, (C6H5CONH2).

Further, benzamide is formed by heating compound 'A' with aqueous ammonia. Therefore, compound 'A' must be benzoic acid.

The given reactions can be explained with the help of the following equations: (Find the attached images)

Hope it helps!!