22. Carboxylic Acid Derivatives: NAS

Propose a mechanism for the reaction of benzyl alcohol with acetyl chloride to give benzyl acetate.

An aqueous solution of a primary or secondary amine reacts with an acyl chloride to form an amide as the major product. However, if the amine is ­tertiary, an amide is not formed. What product is formed? Explain.

What compounds are formed from the reaction of benzoyl chloride with the following reagents?

e. aqueous NaOH

Show how to synthesize the following compounds, using appropriate carboxylic acids and amines.

(b)

What reagent should be used to carry out the following reaction?

The reaction of a nitrile with an alcohol in the presence of a strong acid forms an N-substituted amide. This reaction, known as the Ritter reaction, does not work with primary alcohols.

c. How does the Ritter reaction differ from the acid-catalyzed hydrolysis of a nitrile to form an amide?

Write the mechanism for the acid-catalyzed reaction of an amide with an alcohol to form an ester.

Predict the products of the following reactions.

(k)

What products would you expect to obtain from the following reactions?

a. malonic acid + 2 acetyl chloride

In nucleophilic acyl substitution, which of the following best describes the key mechanistic step that distinguishes it from nucleophilic substitution at alkyl halides?

b. Explain why the rate of aminolysis of an ester cannot be increased by H⁺.

Which of the following is the major product when an acid chloride reacts with ${\mathrm{NH}}_3$ in a nucleophilic acyl substitution reaction?

Show how the following ketones might be synthesized from the indicated acids, using any necessary reagents.

(a) propiophenone from propionic acid (using Friedel–Crafts acylation)

Propose a mechanism for the reaction of aniline with ethyl acetate to give acetanilide. What is the leaving group in your proposed mechanism? Would this be a suitable leaving group for an S_N2 reaction?

Show how you would use acetic anhydride and an appropriate alcohol or amine to synthesize (i) benzyl acetate and (ii) N,N-diethylacetamide.