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

image$\mathop {\xrightarrow{{NaN{O_2}}}}\limits_{HCl} A\,\,\xrightarrow{{CuCN}}B\,\,\mathop {\xrightarrow{{{H_2}}}}\limits_{Ni} C\,\,\xrightarrow{{HN{O_2}}}D$