Isomer $(P) \Rightarrow$ Can be prepared by Gabriel phthalimide synthesis

Isomer $(Q) \Rightarrow$ Reacts with Hinsberg's reagent to give solid insoluble in $NaOH$

Isomer (R) $\Rightarrow$ Reacts with $HONO$ followed by $\beta$-naphthol in $NaOH$ to give red dye.

Isomers $( P ),( Q )$ and $( R )$ respectively are

$C{{H}_{3}}CN+2H\underset{\text{Ether}}{\mathop{\xrightarrow{HCl}}}\,X\underset{{{H}_{2}}O}{\mathop{\xrightarrow{\text{Boiling}}}}\,Y;$   the term $Y$ is:

$CH_3CH_2NH_2 + CHCl_3 + 3KOH \rightarrow (A)+ (B) + 3H_2O,$

the compounds $(A)$ and $(B)$ are respectively