Question

Compound $\left[A\right]$ is an aromatic amine which react with $NaN{O}_2+HCl$ at $273-278K$ and form compound $\left[B\right]$. Compound $\left[B\right]$ react with $HB{F}_4$ and the obtain product on further heating, in the presence of $NaN{O}_2$ and confirm compound $\left[C\right]$. Compound $\left[C\right]$ reduced in the presence of $Sn/HCl$ to re-formed compound $\left[A\right]$. Write general name of ${}^{\prime }{A}^{\prime }{,}^{\prime }{B}^{\prime }$ and ${}^{\prime }{C}^{\prime }$ and write equation of all reaction involved?

Answer 1

Diazotization of aniline with $NaN{O}_2$ / HCl at 273-278K gives benzene diazonium chloride. Balz-Schiemann reaction then replaces diazo group with $-F$ by treatment with $H{B}_4$ to obtain fluorobenzene. F atom is then replaced with nitro group by heating with $NaN{O}_2$. Reduction with Sn/HCl converts nitrobenzene to aniline.