$NBS \xrightarrow{KOBr} (A)$. The product $(A)$ is:

$C_3H_9N$ represents

$STATEMENT-1$: Aniline on reaction with $NaNO_2 / HCl$ at $0^{\circ} C$ followed by coupling with $\beta$-naphthol gives a dark blue coloured precipitate.
$STATEMENT-2$: The colour of the compound formed in the reaction of aniline with $NaNO_2 / HCl$ at $0^{\circ} C$ followed by coupling with $\beta$-naphthol is due to the extended conjugation.

$(i)$ Write structures of different isomeric amines corresponding to the molecular formula,$C_{4}H_{11}N$. $(ii)$ Write $IUPAC$ names of all the isomers. $(iii)$ What type of isomerism is exhibited by different pairs of amines?

Suppose the following reaction:
The product $D$ and $F$ are related as:

Write $IUPAC$ names of the following compounds and classify them into primary,secondary,and tertiary amines.
$(i)$ $(CH_3)_2CHNH_2$
$(ii)$ $CH_3(CH_2)_2NH_2$
$(iii)$ $CH_3NHCH(CH_3)_2$
$(iv)$ $(CH_3)_3CNH_2$
$(v)$ $C_6H_5NHCH_3$
$(vi)$ $(CH_3CH_2)_2NCH_3$
$(vii)$ $m-BrC_6H_4NH_2$