22. Carboxylic Acid Derivatives: NAS

Predict the product of the multistep synthesis reaction shown.

Propose a mechanism for the reaction of benzoic acid with acetyl chloride to give acetic benzoic anhydride.

Suggest the most appropriate reagent for each synthesis, and explain your choice.

(d)

One mole of acetyl chloride is added to a liter of triethylamine, resulting in a vigorous exothermic reaction. Once the reaction mixture has cooled, 1 mole of ethanol is added. Another vigorous exothermic reaction results. The mixture is analyzed and found to contain triethylamine, ethyl acetate, and triethylammonium chloride. Propose mechanisms for the two exothermic reactions.

What compounds are obtained from the following hydrolysis reactions?

d.

a. Which of the following reactions does not give the carbonyl product shown?

b. Which of the reactions that do not occur can be made to occur if an acid catalyst is added to the reaction mixture?

5.

Starting with acetyl chloride, what neutral nucleophile would you use to synthesize each of the following compounds?

f.

Starting with acetyl chloride, what neutral nucleophile would you use to synthesize each of the following compounds?

d.

Propose mechanisms for the nucleophilic acyl substitutions to form N-methylacetamide as shown on the previous page.

Propose a second mechanism for the reaction of benzoic acid with acetyl chloride to give acetic benzoic anhydride. This time, let the other oxygen of benzoic acid serve as the nucleophile to attack the carbonyl group of acetyl chloride. Because proton transfers are fast between these oxygen atoms, it is difficult to differentiate between these two mechanisms experimentally.

b. Explain why the rate of aminolysis of an ester cannot be increased by HO⁻, or RO⁻.

Identify the major and minor products of the following reaction:

a. Which of the following reactions does not give the carbonyl product shown?

b. Which of the reactions that do not occur can be made to occur if an acid catalyst is added to the reaction mixture?

9.

10.

Show how to synthesize the following amines from the indicated starting materials by acylation–reduction.

(a) N-butylpiperidine from piperidine

(b) N-benzylaniline from aniline