Two aromatic compounds (benzene derivatives) A & B of formula ${\mathrm{C}}_8{\mathrm{H}}_{11}\mathrm{N}$ on heating with ${\mathrm{CHCl}}_3$in presence of alc. KOH forms an unpleasant smelling compound. Compound ‘A’ on reaction with ${\mathrm{NaNO}}_2+ \mathrm{HC}l$ at O⁰C followed by treatment with phenol forms an intense red coloured azodye. But compound ‘B’ does not form an azodye on reaction with ${\mathrm{NaNO}}_2+\mathrm{HCl}$followed by treatment with phenol.