An aromatic compound $A$ on treatment with aqueous ammonia and heating forms compound $B$,which on heating with $Br_2$ and $KOH$ forms a compound $C$ of molecular formula $C_6H_7N$. Write the structures and $IUPAC$ names of compounds $A, B$,and $C$.

(N/A) The reaction of compound $B$ with $Br_2$ and $KOH$ to form compound $C$ $(C_6H_7N)$ is a Hoffmann bromamide degradation reaction. This indicates that $C$ is an amine and $B$ is an amide. The amine with molecular formula $C_6H_7N$ is aniline $(C_6H_5NH_2)$,which has the $IUPAC$ name benzenamine.
Since $C$ is aniline,the corresponding amide $B$ must be benzamide $(C_6H_5CONH_2)$.
Benzamide is formed by heating benzoic acid $(A)$ with aqueous ammonia. Thus,compound $A$ is benzoic acid $(C_6H_5COOH)$.
The structures and names are:
$A$: Benzoic acid $(C_6H_5COOH)$
$B$: Benzamide $(C_6H_5CONH_2)$
$C$: Benzenamine or Aniline $(C_6H_5NH_2)$
The reaction sequence is:
$C_6H_5COOH$ $\xrightarrow{NH_3, \Delta} C_6H_5CONH_2$ $\xrightarrow{Br_2, KOH} C_6H_5NH_2$