Acylation of Amines by Acid Chlorides

Propose a mechanism to show the individual alkylations that form this quaternary ammonium salt. 

Reaction with a large excess of ammonia. Because ammonia is inexpensive and has a low molecular weight, it is convenient to use a very large excess. Addition of a primary alkyl halide to a large excess of ammonia forms the primary amine, and the probability of dialkylation is small. Excess ammonia is simply allowed to evaporate. 

Show how you would use direct alkylation to synthesize the following compounds, (a) benzyltrimethylammonium iodide (b) 1-pentanamine (c) benzylamine 

Primary and secondary amines react with acid halides to form amides. This reaction is a nucleophilic acyl substitution the replacement of a leaving group on a carbonyl carbon by a nucleophile. We will study nucleophilic acyl substitution in detail in Chapters 20 and 21. In this case, the amine replaces chloride ion. 

Step 1 A nucleophile attacks the strongly electrophilic carbonyl group of the acid chloride. 

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Alkylation of Amines by Alkyl Halides 899 19-12 Acylation of Amines by Acid Chlorides 900... 

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