$(ii)\,R\, - \,CONHBr\, + \,KOH\, \to \,R\, - \,NCO\, + \,KBr\, + \,{H_2}O$
$(iii)\,R\, - \,NCO\, + \,2KOH\,\, \to \,R\, - \,N{H_2}\, + \,{K_2}C{O_3}$
${C_2}{H_5}N{H_2}\,\xrightarrow{{HN{O_2}}}a$
${C_2}{H_5}N{H_2}\,\xrightarrow{{{C_6}{H_5}CHO}}b$
${C_2}{H_5}N{H_2}\,\xrightarrow{{NOCl}}c$
${C_2}{H_5}N{H_2}\,\xrightarrow{{{C_6}{H_5}S{O_2}Cl}}d$