Nitrogen compounds

Amines and nitriles

Amines contain N with a lone pair. Primary amines form when halogenoalkanes react with excess ammonia in ethanol, heated under pressure (excess limits further substitution to secondary and tertiary amines). Nitriles form from halogenoalkanes + KCN (ethanol) or carbonyls + HCN (hydroxynitriles); they can be hydrolysed (acid, reflux) to carboxylic acids or reduced (LiAlH₄, or H₂/Ni) to primary amines, giving an amine with one extra carbon and no mixture. Amines are bases: the N lone pair accepts H⁺, forming ammonium salts: $\mathrm{RNH_2+HCl\rightarrow RNH_3^+Cl^-}$.