Q.Explain Ammonolysis of alkyl halides.

Step 1. Define ammonolysis (section 13.3.1). Ammonolysis of an alkyl halide is the nucleophilic substitution reaction in which alcoholic ammonia's own nitrogen lone pair displaces the halide leaving group, replacing it with an -NH2 group, giving a primary amine as the intended product.

Step 2. State the reaction conditions. The reaction is carried out with the alkyl halide heated together with an EXCESS of alcoholic ammonia solution, in a sealed tube, at 373 K (ammonia's own gaseous nature at ordinary pressure means a sealed, pressurised system is needed to keep enough of it in solution).

Step 3. Explain the key complication -- over-alkylation. The primary amine formed in this first substitution step is itself a STRONGER nucleophile than the ammonia it came from, so it competes with the remaining ammonia for any further alkyl halide present -- reacting on to give secondary amine, then tertiary amine, and ultimately quaternary ammonium salt, unless ammonia is genuinely present in large excess (which keeps the probability of the amine, rather than ammonia, encountering the next molecule of alkyl halide low). …

Explaining section 13.3.1's ammonolysis reaction in full -- mechanism, conditions, the over-alkylation complication, substrate reacti …

• Omitting the over-alkylation complication entirely, describing ammonolysis as though it cleanly stops at the primary amine regardless of conditions, when the section is explicit that genuine EXCESS ammonia is required to suppress further reaction. …