How will you distinguish between Aniline and N-methylaniline?

Write the structures of the compounds $\mathrm{A}, \mathrm{B}$ and $\mathrm{C}$ in the following reaction?

${\mathrm{CH}}_3-\mathrm{COOH}\stackrel{{\mathrm{NH}}_3/∆}{\to } \mathrm{A} \stackrel{{\mathrm{Br}}_2/\mathrm{KOH}}{\to } \mathrm{B}\stackrel{{\mathrm{CHCl}}_3+\mathrm{alc}. \mathrm{KOH}}{\to } \mathrm{C}$

Write the structures of compounds $\mathrm{A}, \mathrm{B}$ and $\mathrm{C}$ in the following reaction.

${\mathrm{C}}_6{\mathrm{H}}_5{{\mathrm{N}}_2}^{+}{{\mathrm{BF}}_4}^{-}\stackrel{{\mathrm{NaNO}}_2/\mathrm{Cu}}{\to } \mathrm{A} \stackrel{\mathrm{Fe}/\mathrm{HCl}}{\to } \mathrm{B}\stackrel{{\mathrm{CH}}_3\mathrm{COCl}/ \mathrm{Pyridine}}{\to } \mathrm{C}$

Why aniline does not undergo Friedel-Crafts reaction?