In carbylamine reaction, isocyanide (bad smelling compound) is obtained when primary amine (aliphatic as well as aromatic) reacts with chloroform in the presence of alkali. This reaction proceeds through dichlorocarbene intermediate which is obtained by the reaction of chloroform with alkene.
$\mathrm{C}\mathrm{H}\mathrm{C}{\mathrm{l}}_3+\mathrm{K}\mathrm{O}\mathrm{H}\to \mathrm{K}\mathrm{C}\mathrm{l}+{\mathrm{H}}_2\mathrm{O}+\underset{\text{Dichlorocarbene'Z'}}{:\mathrm{C}\mathrm{C}{\mathrm{l}}_2}$

The $\mathrm{X}=\mathrm{R}\mathrm{N}{\mathrm{H}}_2$ and $\mathrm{Y}=\mathrm{R}\mathrm{N}\mathrm{C}$ .