\({R}-{NH}_{2} \stackrel{{CHCl}_{3}}{\longrightarrow} {R}-\stackrel{\oplus}{{N}} \equiv \stackrel{\ominus}{{C}} \xrightarrow[({HCl})]{{H}_{3} {O}^{\oplus}} {R}-{NH}_{2}+{HCOOH}\)
\(1^{\circ}\) amine \(_{(A)}\) \(\quad\quad\)Isonitrile \(_{(B)}\) \(\quad\quad(C)\)
image $\mathop {\xrightarrow{{NaN{O_2}}}}\limits_{HCl} A\,\,\xrightarrow{{CuCN}}B\,\,\mathop {\xrightarrow{{{H_2}}}}\limits_{Ni} C\,\,\xrightarrow{{HN{O_2}}}D$