(i) When an alkyl or benzyl halide reacts with an ethanolic solution of ammonia, the halogen atom is replaced by an amino ( – NH2) group in a nucleophilic substitution process. Ammonolysis is the name for the breakage of the carbon-halogen bond.
When a strong base, such as sodium hydroxide, is used to treat this substituted ammonium salt, the amine is produced.
Despite the fact that primary amine is the main result, this procedure creates a combination of primary, secondary, and tertiary amines, as well as a quaternary ammonium salt, as illustrated.
(ii)
The process of adding an acetyl group into a molecule is known as acetylation (or ethanoylation).
When treated with acid chlorides, anhydrides, or esters, aliphatic and aromatic primary and secondary amines undergo a nucleophilic substitution acetylation process. The acetyl group replaces the hydrogen atom of the –NH2 or >NH group in this reaction, resulting in the creation of amides. To shift the equilibrium to the right-hand side, the HCl that is created during the reaction is eliminated practically as soon as it is produced. This reaction takes place in the presence of a base (such as pyridine) that is more powerful than the amine.
The process that occurs when amines react with benzoyl chloride is also known as benzoylation. The following is one of the examples:
(iii) The synthesis of aliphatic primary amines using Gabriel phthalimide is a useful and significant approach. It contains the reaction of phthalimide with ethanolic potassium hydroxide to produce phthalimide potassium salt. This salt is then heated with an alkyl halide, followed by alkaline hydrolysis, resulting in the main amine.
