The reaction of acetic acid with ammonia followed by heating gives acetamide. This is followed by Hofmann bromamide reaction to obtain methylamine. CH3−COOH(i)NH3−−−−−−−→(ii)Δ−H2OCH3−CONH2Br2/KOH−−−−−−−−−−−−−−−−−→Hofmann bromamide reactionCH3NH2
(iv) Aniline to benzene.
The diazotization of aniline with nitrous acid at low temperature gives benzene diazonium chloride. The diazo group is then replaced with H atom by treatment with hypophosphorus acid to obtain benzene.