Question

Considering the reaction of Aniline with $NaNO_2/HCl$ at $0-5^\circ$C to give X, which is then reacted with $H_3PO_2$, identify X and Y :
 
 

• A. A
• B. B
• C. C
• D. D

Hint:

$H_3PO_2$ is a standard reagent to remove the $-NH_2$ group (via the diazonium salt) from an aromatic ring.

Answer 1

The Correct Option is A

Step 1: Aniline + $NaNO_2/HCl$ (Diazotization) $\rightarrow$ Benzene diazonium chloride ($Ph-N_2^+Cl^-$). This is **X**.
Step 2: $H_3PO_2$ (hypophosphorous acid) or $CH_3CH_2OH$ acts as a reducing agent for diazonium salts.
Step 3: It reduces the diazonium group to a Hydrogen atom, yielding **Benzene** ($Ph-H$). This is **Y**.