The aromatic amine shown is heated with $CHCl X_{3}$ / $KOH$ ; the foul-smelling product is hydrogenated over Ni to a secondary amine, which is then treated with cold $NaNO X_{2}$ / $HCl$ . Which structure is the final product?

Answer: C

The compound shown is aniline. The carbylamine reaction gives phenyl isocyanide; catalytic hydrogenation of the isocyanide carbon turns

\ce{-N^+#C^-}

into

- NH - CH X_{3}

, giving N-methylaniline. This secondary amine is N-nitrosated by nitrous acid to give N-methyl-N-nitrosoaniline.