Carboxylic Acids and Their Derivatives— Nucleophilic Acyl Substitution

Nylon 6,6, a polymer composed of many amide bonds, was the first synthetic fiber and one of the most lucrative products ever invented at DuPont. Because nylon is strong and durable, and can be spun into a fiber that resembles the silk produced by silkworms, nylon found immediate use in making parachutes, clothing, stockings, and rope. Nylon 6,6 is a polyamide that can be prepared by joining a diacid chloride and a diamine together. In Chapter 22, we learn about amides and other acyl derivatives of carboxylic acids. 

Chapter 22 Carboxylic Acids and Their Derivatives—Nucleophilic Acyl Substitution 

Chapter 22 continues the study of carbonyl compounds with a detailed look at nucleophilic acyl substitution, a key reaction of carboxylic acids and their derivatives. Substitution at sp hybridized carbon atoms was introduced in Chapter 20 with reactions involving carbon and hydrogen nucleophiles. In Chapter 22, we learn that nucleophilic acyl substitution is a general reaction that occurs with a variety of heteroatomic nucleophiles. This reaction allows the conversion of one carboxylic add derivative into another. Every reaction in Chapter 22 that begins with a carbonyl compound involves nucleophilic substitution. Chapter 22 also discusses the properties and chemical reactions of nitriles, compounds that contain a carbon-nitrogen triple bond. Nitriles are in the same carbon oxidation state as carboxylic acids, and they undergo reactions that form related products. 

Chapter 22 focuses on carbonyl compounds that contain an acyl group bonded to an electronegative atom. These include the carboxylic acids, as well as carboxylic acid derivatives that can be prepared from them acid chlorides, anhydrides, esters, and amides. 

Anhydrides contain two carbonyl groups joined by a single oxygen atom. Symmetrical anhydrides have two identical alkyl groups bonded to the carbonyl carbons, and mixed anhydrides have two different alkyl groups. Cyclic anhydrides are also known. 

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Chapter 22 Carboxylic Acids and Their Derivatives—Nucleophilic Acyl Substitution Thus, the following trends result ... 

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