Question
Two isomeric compounds $(A$ and $B)$ have $\ce{ C_4H_{11}N}$ molecular formula react with $\ce{HNO_2}$ and forms compounds $(C)$ and $(D). C$ is hardly oxidised but it reacts immediately with Lucas reagent whereas $D$ reacts with Lucas reagent in $5$ minutes and it also gives haloform reaction. Identify $\ce{A, B, C}$ and $\ce{D}$.

group it gives haloform reaction.