


${C_2}{H_5}N{H_2}\,\xrightarrow{{HN{O_2}}}a$
${C_2}{H_5}N{H_2}\,\xrightarrow{{{C_6}{H_5}CHO}}b$
${C_2}{H_5}N{H_2}\,\xrightarrow{{NOCl}}c$
${C_2}{H_5}N{H_2}\,\xrightarrow{{{C_6}{H_5}S{O_2}Cl}}d$
image
$\mathop {C{H_3} - C{H_2} - N{H_2}}\limits_{\mathop 2\limits } \,$$\,\mathop {{{(C{H_3})}_2}NH}\limits_{\mathop 3\limits } $
$\mathop {C{H_3} - \mathop {\mathop C\limits^{||} }\limits^O - N{H_2}}\limits_4 $