Question

$C_6{H}_5-N=N-C_6{H}_5$ is the product of which of the following given reactions?

• A. Oxidised product of aniline in $K_{2}C{r}_2{O}_7+H_{2}S{O}_4$.
• B. Product of nitro benzene in the presence of $LiAl{H}_4$.
• C. Product of nitro benzene in neutral medium.
• D. Product of acidic reduction of nitro benzene.

Answer 1

Answer: (B)

Product of nitro benzene in the presence of $LiAl{H}_4$.

When nitrobenzene is reduced in an alkaline medium, nitrosobenzene and phenylhydroxylamine are obtained. These intermediates react to form azoxybenzene.
Azoxybenzene on further reduction forms azobenzene and hydrazobenzene. Thus, when nitrobenzene is reduced in an alkaline medium with reducing agent lithium alunimum hydride, azobenzene $(C_6{H}_{5}N=N-C_6{H}_5)$ is obtained.