Chapter 10, Problem 10.33P

Interpretation Introduction

Interpretation:

The complete, detailed mechanism and the major product for the given reaction is to be drawn.

Concept introduction:

If an alkyl halide is treated with an excess of ammonia, then the ${\text{1}}^{\text{°}}$ amine (${\text{RNH}}_{\text{2}}$) is formed in a mixture that also contains a $2^{\text{°}}$ amine (${\text{R}}_2{\text{NH}}_{\text{2}}$), a $3^{\text{°}}$ amine (${\text{R}}_3\text{N}$), and a $4^{\text{°}}$ ammonium ion (${\text{R}}_4{\text{N}}^{+}$). The primary amine that is formed from the first alkylation is also nucleophilic at the N atom. It can therefore react with any unreacted alkyl halide species remaining in the solution, leading to further alkylations. The same process, i.e., an ${\text{S}}_{\text{N}}\text{2}$ reaction followed by deprotonation can occur a third time to yield the tertiary amine. The tertiary amine is nucleophilic, too, so it can react in a fourth ${\text{S}}_{\text{N}}\text{2}$ reaction to yield the quaternary ammonium ion.