(image) $+ NaNO_2+HCl \rightarrow $ product

image $\xrightarrow{{A{c_2}O}}A\mathop {\xrightarrow{{B{r_2}}}}\limits_{C{H_3}COOH} B\mathop {\xrightarrow{{{H_2}O}}}\limits_{{H^ + }} C$ would be

Figure $\xrightarrow[{0\, - \,5\,\,{\,^o}C}]{{HN{O_2}}}$ $P$ $\xrightarrow{{HB{F_4}}}Q$ $\xrightarrow[{Cu,\,\,\Delta }]{{NaN{O_2}}}R$