Functional Derivatives of Carboxylic Acid

9 Key excerpts on "Functional Derivatives of Carboxylic Acid"

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  eBook - PDF

  Experimental Organic Chemistry

  A Miniscale & Microscale Approach

  • John Gilbert, Stephen Martin(Authors)
  • 2015(Publication Date)
  • Cengage Learning EMEA

    (Publisher)

  759 C H A P T E R Carboxylic Acids and Their Derivatives The chemistry of organic compounds containing the carbon-oxygen double bond is arguably richer than that of any other class of organic molecules. In the experi-ments in Chapter 18, there is an opportunity to learn that the chemistry of alde-hydes and ketones is determined by the presence of the carbonyl functional group. In this chapter, you will be able to study the chemistry associated with carboxylic acids and some of their derivatives. These compounds contain a carbon-oxygen double bond, in which the carbonyl carbon atom bears an additional heteroatom such as oxygen, nitrogen, or halogen. The presence of this heteroatom dramatically changes the chemical properties of the carbonyl group, but in ways that you will learn are predictable. Derivatives of carboxylic acids are commonplace in materials we encounter daily and include fabrics, antibiotics, and insecticides, to name a few. In the experiments in this chapter, you will be introduced to the varied chemistry and the importance of carboxylic acid derivatives by preparing compounds having use as an anesthetic and as an insect repellent. You will also have the opportunity to study a fascinating chemical reaction that produces light, resulting from decomposi-tion of a compound you have synthesized. 20.1 I N T R O D U C T I O N Carboxylic acids are characterized by the presence of the carboxyl functional group , – CO 2 H, which is composed of a carb onyl group and a hydr oxyl group, and have the general structural formula 1 in which R is a hydrogen or an alkyl or an aryl substituent. Their derivatives arise by replacing the hydroxyl group in 1 with other heteroatom substituents such as Cl in an acid chloride , O = COR 1 in an acid anhydride , OR 2 in an ester , and NR 3 R 4 in an amide .

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  Understanding Advanced Organic and Analytical Chemistry

  The Learner's ApproachRevised Edition

  • Kim Seng Chan, Jeanne Tan;;;(Authors)
  • 2016(Publication Date)
  • WS EDUCATION

    (Publisher)

  CHAPTER 10

  Carboxylic Acids and Their Derivatives

  10.1 Introduction

  Carboxylic acids are organic compounds that contain the following carboxyl functional group, denoted as –COOH.

  From the constitutional/structural formula, the carboxyl functional group is a composite of a carbonyl functional group and a hydroxyl group. Similar to that in carbonyl compounds, the carbon atom of the carboxyl functional group is sp2 hybridized and trigonal planar in shape. Thus, it is not surprising that carboxylic acids possess physical and chemical properties similar to both the carbo nyl and hydro

  xyl

  compounds.

  Derivatives of carboxylic acids have the –OH group substituted. For instance, esters contain the functional group –COOR, and acid chlorides the –COCl group.

  10.2 Nomenclature

  Carboxylic acids are named with the suffix –oic acid. Other substituents are named as prefixes accompanied by the appropriate positional numbers. If the carboxylic acid group is considered a substituent, then it is named as the –carboxy prefix (notice that the prefix is not “carboxyl”).

  10.3 Physical Properties

  10.3.1 Melting and Boiling Points

  Melting and boiling points increase with increasing carbon chain length (Table 10.1 ) and decrease with increasing degree of branching. As with alcohols, the trend is accounted for by the increasing strength of instantaneous dipole–induced dipole (id–id) attractive forces due to the greater number of electrons accompanying the increasing carbon chain length, rather than hydrogen-bonding.

  Table 10.1

  The boiling points of carboxylic acids are higher than those of their isomeric ester counterparts (Table 10.2

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  Brown's Introduction to Organic Chemistry

  • William H. Brown, Thomas Poon(Authors)
  • 2017(Publication Date)
  • Wiley

    (Publisher)

  • The functional group of a carboxylic anhydride is two acyl groups bonded to an oxygen. • Symmetrical anhydrides are named by changing the suffix acid in the name of the parent carboxylic acid to anhydride. • The functional group of a carboxylic ester is an acyl group bonded to OR or OAr. • An ester is named by giving the name of the alkyl or aryl group bonded to oxygen first, followed by the name of the acid, in which the suffix ‐ic acid is replaced by the suffix ‐ate. • A cyclic ester is given the name lactone. • The functional group of an amide is an acyl group bonded to a trivalent nitrogen. • Amides are named by dropping the suffix ‐oic acid from the IUPAC name of the parent acid, or ‐ic acid from its common name, and adding ‐amide. • A cyclic amide is given the name lactam. 14.2 What Are the Characteristic Reactions of Carboxylic Acid Derivatives? • A common reaction theme of functional derivatives of car- boxylic acids is nucleophilic acyl addition to the carbonyl carbon to form a tetrahedral carbonyl addition intermedi- ate, which then collapses to regenerate the carbonyl group. The result is nucleophilic acyl substitution. 14.3 What Is Hydrolysis? • Hydrolysis is a chemical process whereby a bond (or bonds) in a molecule is broken by its reaction with water. • Hydrolysis of a carboxylic acid derivative results in a car- boxylic acid. 14.4 How Do Carboxylic Acid Derivatives React with Alcohols? • Carboxylic acid derivatives (except for amides) react with alcohols to give esters. • The reaction conditions required (i.e., neutral, acidic, or basic) depend on the type of derivative. 14.5 How Do Carboxylic Acid Derivatives React with Ammonia and Amines? • Carboxylic acid derivatives (except for amides) react with ammonia and amines to give amides.

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  Organic Reactions and their nomenclature

  • Ramesh Chandra, Snigdha Singh, Aarushi Singh(Authors)
  • 2019(Publication Date)
  • Arcler Press

    (Publisher)

  Carboxylic Acid Reactions and Uses 5 CONTENTS 5.1. Introduction .................................................................................... 166 5.2. Nomenclature Of Carboxylic Acids ................................................ 167 5.3. Carboxylic Acid Examples .............................................................. 167 5.4. Properties Of Carboxylic Acids ....................................................... 168 5.5. Physical Properties Of Carboxylic Acids ........................................ 169 5.6. The Acidity Of Carboxylic Acids .................................................... 171 5.7. Carboxylic Acid Derivatives And Acyl Groups ................................ 174 5.8. The Nucleophilic Acyl Substitution Reaction .................................. 177 5.9. The Relative Reactivity Of Carboxylic Acid Derivatives ................... 180 5.10. Uses Of Carboxylic Acids ............................................................. 184 References ............................................................................................. 195 Organic Reactions and their nomenclature 166 5.1. INTRODUCTION A carboxylic acid is an organic complex having a (COOH) carboxyl functional group. They come about broadly in nature and are also unnaturally manufactured by humans. Upon deprotonation (removal of a proton), carboxylic acids produce a carboxylate anion with the general formula R-COO–, which can give a variety of beneficial salts like soaps (Sáenz-Galindo et al., 2018). The most important functional group that present are the carboxylic acids C=O. This sort of organic compounds can be attained by different ways, some carboxylic acids, for example, fumaric acid, citric acid or lactic acid are formed from by fermentation most of these kinds of carboxylic acids are useful in the food industry (Oguz et al., 2017).

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  Organic and Biological Chemistry

  • H. Stephen Stoker(Author)
  • 2015(Publication Date)
  • Cengage Learning EMEA

    (Publisher)

  C O OH O B Cyclic carboxylic acids do not exist; having the carboxyl carbon atom as part of a ring system creates a situation where the carboxyl carbon atom would have five bonds. The nonexistence of cyclic carboxylic acids parallels the nonexistence of cyclic aldehydes (Section 4-3). ◀ A carboxylic acid derivative is an organic compound that can be synthesized from or converted into a carboxylic acid. Four important families of carboxylic acid deriva-tives are esters, acid chlorides, acid anhydrides, and amides. The group attached to the carbonyl carbon atom distinguishes these derivative types from each other and also from carboxylic acids. R O C O OR 9 Ester B O R O C O Cl Acid chloride B O R O C O NH 2 Amide B O R O C O O O C O R Acid anhydride B O B O Carbonyl Compounds and Acyl Compounds Generalized structures for carboxylic acids and carboxylic acid derivatives all have the form R O C O Z B O Structurally, these compound types differ from each other only in the identity of the Z entity present, as shown in the preceding set of carboxylic acid derivative structures. Carboxylic acids and their derivatives have a common structural component, which is called an acyl group . R O C O OH B O acyl group Carboxylic acid R O C O OR B O acyl group Ester R O C O Cl B O acyl group Acid chloride R O C O O O C O R B O B O acyl group Acid anhydride R O C O NH 2 B O acyl group Amide ▶ The term carboxyl is a contraction of the words carb onyl and hydr oxyl . ▶ General formulas for carboxylic acids containing alkyl and aryl groups, respectively, are R ! COOH and Ar ! COOH Copyright 2016 Cengage Learning. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part. Due to electronic rights, some third party content may be suppressed from the eBook and/or eChapter(s). Editorial review has deemed that any suppressed content does not materially affect the overall learning experience.

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  Chemistry for Pharmacy Students

  General, Organic and Natural Product Chemistry

  • Lutfun Nahar, Satyajit Sarker, Professor Satyajit D. Sarker(Authors)
  • 2019(Publication Date)
  • Wiley

    (Publisher)

  4 .

  4.4.2.8 Reactions of Carboxylic Acids

  The most important reactions of carboxylic acids are the conversion to various carboxylic acid derivatives; for example, acid chlorides, acid anhydrides and esters. Esters are obtained by the reaction of carboxylic acids and alcohols. The reaction is acid‐catalysed and known as Fischer esterification (see Section 5.6.5.1). Acid chlorides are synthesized from carboxylic acids by the treatment of thionyl chloride (SOCl2 ) or oxalyl chloride [(COCl)2 ], and acid anhydrides are produced from two carboxylic acids. A summary of the conversion of carboxylic acid is presented next. All these conversions involve nucleophilic acyl substitutions (see Section 5.6.5).

  4.4.2.9 Carboxylic Acid Derivatives

  Carboxylic acid derivatives are compounds that possess an acyl group (R─C═O) linked to an electronegative atom; for example, ─Cl, ─CO2 R, ─OR, ─NH2 . They can be converted to carboxylic acids via simple acidic or basic hydrolysis. The important acid derivatives are acid chlorides, acid anhydrides, esters and amides. Usually nitriles are also considered as carboxylic acid derivatives. Although nitriles are not directly carboxylic acid derivatives, they are conveniently hydrolysed to carboxylic acids by acid or base catalysts. Moreover, nitriles can be easily prepared through dehydration of amides, which are carboxylic acid derivatives.

  4.4.2.10 Reactivity of Carboxylic Acid Derivatives

  The reactivity of carboxylic acid derivatives varies greatly in the nucleophilic acyl substitution reactions, where one nucleophile replaces a leaving group on the acyl carbon. In general, it is easy to convert more reactive derivatives into less reactive derivatives. Therefore, an acid chloride is easily converted to an anhydride, ester or amide, but an amide can only be hydrolysed to a carboxylic acid. Acid chlorides and acid anhydrides are hydrolysed easily, whereas amides are hydrolysed slowly in boiling alkaline water.

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  Organic Chemistry

  An Acid-Base Approach, Third Edition

  • Michael B. Smith(Author)
  • 2022(Publication Date)
  • CRC Press

    (Publisher)

  18 Carboxylic Acid Derivatives and Acyl Substitution

  DOI: 10.1201/9781003174929-18

  The video clips for this chapter are available at: https://routledgetextbooks.com/textbooks/9780367768706/chapter-18.php

  The acyl addition reactions of nucleophiles with aldehydes and ketones are discussed in Chapter 16 . Carboxylic acid derivatives also contain a carbonyl unit, but they have a leaving group attached to the acyl carbon that facilitates acyl substitution reactions.

  To begin this chapter, you should know the following points:

  • Nomenclature (Sections 4.3, 5.1, 5.2, 5.3, 5.5, and 5.6).
  • The carboxyl functional group (Section 5.6.3).
  • The acid-base properties of carboxylic acids (Sections 6.2 and 6.3).
  • The CIP rules (Section 9.2).
  • The π-bond (Sections 5.1 and 5.2).
  • Aldehydes and ketones (Sections 5.6.1,2).
  • Acyl addition (Sections 16.1 and 16.2).
  • Mechanisms (Section 7.10).
  • Intermediates (Sections 7.2, 10.1, and 10.10).
  • Lewis acids and bases (Sections 2.7 and 6.8).
  • Nucleophiles (Sections 6.9 and 11.1–11.3).
  • Leaving groups (Section 11.1).
  • The SN 2 reaction (Section 11.2.)
  • Grignard reagents and organolithium reagents (Sections 16.2).
  • Organocuprates (Section 14.4).
  • The mechanism of acetal and ketal formation (Section 16.4.2).
  • Oxidation reactions of peroxyacids (Sections 15.4).
  • Reagents for the conversion of alcohols to alkyl halides (Section 11.5).

  18.1 Carboxylic Acids

  Carboxylic Acids

  Carboxylic acids were introduced in Section 5.9.3. Carboxylic acids contain a carbonyl that is connected to an OH unit in a COOH unit called the carboxyl group . As the name implies, carboxylic acids are good Brønsted-Lowry acids, with pKa values that typically range from 1–6 (Sections 6.2–6.3). An acid-base reaction of a carboxylic acid with sodium amide is shown, generating the resonance-stabilized carboxylate anion and the conjugate acid, ammonia (Section 6.3).

  The IUPAC nomenclature for carboxylic acids identifies the longest continuous chain for the acid that contains the CO2 H unit. The carboxyl is the locant and it is always C1 so 1- is omitted from the name. The suffix for carboxylic acids is -oic acid

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  Organic Chemistry, Student Study Guide and Solutions Manual

  • David R. Klein(Author)
  • 2017(Publication Date)
  • Wiley

    (Publisher)

  Chapter 20 Carboxylic Acids and Their Derivatives Review of Concepts Fill in the blanks below. To verify that your answers are correct, look in your textbook at the end of Chapter 20. Each of the sentences below appears verbatim in the section entitled Review of Concepts and Vocabulary.  Treatment of a carboxylic acid with a strong base yields a ________________ salt.  The pKa of most carboxylic acids is between ____ and _____.  Using the Henderson-Hasselbalch equation, it can be shown that carboxylic acids exist primarily as ________________________ at physiological pH.  Electron-____________ substituents can increase the acidity of a carboxylic acid.  When treated with aqueous acid, a nitrile will undergo _______________, yielding a carboxylic acid.  Carboxylic acids are reduced to ____________ upon treatment with lithium aluminum hydride or borane.  Carboxylic acid derivatives exhibit the same _____________ state as carboxylic acids.  Carboxylic acid derivatives differ in reactivity, with _________________ being the most reactive and ________________ the least reactive.  When drawing a mechanism, avoid formation of a strong ___________ in acidic conditions, and avoid formation of a strong ____________ in basic conditions.  When a nucleophile attacks a carbonyl group to form a tetrahedral intermediate, always reform the carbonyl group if possible, but avoid expelling _____ or ______.  When treated with an alcohol, acid chlorides are converted into _________________.  When treated with ammonia, acid chlorides are converted into _____________.  When treated with a _____________ reagent, acid chlorides are converted into alcohols with the introduction of two alkyl groups.  The reactions of anhydrides are the same as the reactions of ________________ except for the identity of the leaving group.  When treated with a strong base followed by an alkyl halide, carboxylic acids are converted into __________.

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  Organic Chemistry Study Guide

  Key Concepts, Problems, and Solutions

  • Robert J. Ouellette, J. David Rawn(Authors)
  • 2014(Publication Date)
  • Elsevier

    (Publisher)

  21

  Carboxylic Acid Derivatives

  Keys to the Chapter

  21.1 Nomenclature of Carboxylic Acid Derivatives

  The names of the acid derivatives with the exception of nitriles resemble those of the structurally related carboxylic acid. The acid halides are named using -oyl halide in place of -oic acid of carboxylic acids. Compounds with an acid halide bonded to a ring carbon atom are named by appending carbonyl halide to the name of the alkane. The acid anhydrides are named using -oic anhydride in place of -oic acid of carboxylic acids.

  Esters are named by the name of the alkyl group bonded to the bridging oxygen atom followed by the name of the acid, with -oate replacing -oic acid. Compounds with the acid portion bonded to a ring carbon atom are named by appending carboxylate to the name of the alkane. Lactones are named by adding lactone as a separate word to the name of the hydroxy acid.

  Amides are named using amide in place of -oic acid of carboxylic acids. Compounds with an amide bonded to a ring carbon atom are named by appending carboxamide to the name of the alkane. The prefix N- is used to identify alkyl or aryl groups bonded to the nitrogen atom of the amide. Lactams are named by adding lactam as a separate word to the name of the amino acid. Nitrites are named by adding nitrile to the name of the related alkane. The name includes the carbon of the cyano group.

  21.2 Physical Properties of Acyl Derivatives

  Acid halides and acid anhydrides are polar compounds and have physical properties that resemble those of structurally similar carbonyl derivatives of similar molecular weight.

  Esters are polar molecules, but they cannot form intermolecular hydrogen bonds like carboxylic acids do. Hence, esters have lower solubility in water and have lower boiling points than carboxylic acids.

  The lower-molecular-weight amides are soluble in water as a result of hydrogen bonding to water molecules. The melting points of primary and secondary amides are higher than those for alkanes of similar molecular weight because of intermolecular hydrogen bonding. Tertiary amides have lower melting points than isomeric primary and secondary amides because they do not have an N—H bond to form intermolecular hydrogen bonds.

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