Practice Questions

Question 1

Which of the following acetylating conditions will convert diethylamine into an amide at the fastest rate?
a) acetic acid/HCl
b) acetic anhydride
c) acetyl chloride
d) ethyl acetate

Answer 1

◦ C
◦ The conversion of an amine to an amide is a nucleophilic addition-elimination reaction, where the amine acts as the nucleophile - therefore looking for the option with the best electrophile which would increase the reaction rate
◦ The relative reaction rates of carboxylic acid derivatives (amide < ester < anhydride < acid halide), eliminated B and D.
◦ B/c amines are nucleophilic and basic, they will be protonated by both the HCl and the acetic acid to yield a non-nucleophilic conjugate acid - which eliminates A