Question

The reagents that can be used to convert benzene diazonium chloride to benzene are ________________.

• A. $LiAl{H}_4$
• B. $H_{3}P{O}_2$
• C. $SnC{l}_2/HCl$
• D. $C{H}_{3}C{H}_{2}OH$

Answer 1

Answer: (B), (D)

$C{H}_{3}C{H}_{2}OH$

Analysing the options

Option $\left(A\right)$


Options $\left(B\right)$ and \((C))
Conversion of benzene diazonium chloride to benzene
Mild reducing agents like hypophosphorous acid (phosphinic acid) or ethanol reduce diazonium salts to benzene and themselves get oxidised to phosphorous acid and ethanal, respectively.

$Ar—N_2^{+}C{l}^{-}+H_{3}P{O}_2+H_{2}O\to ArH+N_2+H_{3}P{O}_3+HCl$
$Ar—N_2^{+}C{l}^{-}+C{H}_{3}C{H}_{2}OH\to ArH+N_2+C{H}_{3}CHO+HCl$

Option $\left(D\right)$


So, options $\left(B\right)$ and $\left(C\right)$ are the correct answers.