Chemeketa Community College Chapter 14: Carboxylic Acids, Esters, Amines & Amides Larry Emme Chemeketa Community College

Chapter Outline Carboxylic Acids Properties of Acids Esters Amines Amides

A poem by Ogden Nash The ant has made himself illustrious Through constant industry industrious So what? Would you be calm and placid If you were full of formic acid?

Carboxylic Acids A carboxylic acid contains a carboxyl group, which is a carbonyl group (C=O) attached to a hydroxyl group (—OH). is found on carbon 1 in carboxylic acids. hydroxyl group or CH3COOH carbonyl group

CH3—CH3 Ethane CH3—COOH Ethanoic acid IUPAC Names In the IUPAC names of carboxylic acids the -e in the alkane name is replaced with -oic acid. CH4 Methane HCOOH Methanoic acid CH3—CH3 Ethane CH3—COOH Ethanoic acid substituents are numbered from the carboxyl carbon 1. 3-methylbutanoic acid

Names and Sources of Some Carboxylic Acids

Common Names for Acids HCOOH Formic Formica (ant) CH3COOH Acetic Acetum (sour) CH3CH2COOH Propionic Pro (first) + Pion (fat) CH3(CH2)2COOH Butyric Butyrum (butter) CH3(CH2)3COOH Valeric Valere (strong) CH3(CH2)4COOH Caproic Caper (goat) CH3(CH2)5COOH Enanthic Vine (wine) CH3(CH2)6COOH Caprylic Caper (goat) http://en.wikipedia.org/wiki/Carboxylic_acid

Common Carboxylic Acids methanoic acid (formic acid) ethanoic acid (acetic acid)

Nail Fungus Treatment by NonyX Nail Gel - End Yellow Nails Price: $23.95 Vendor: Brand: Xenna Corp Availability: In Stock-Ships in 24 Hours Product Description Discolored Fingernails or Toenails? Just like a superhero, NonyX® Nail Gel clears out the keratin debris that causes the problem. If your toenails or fingernails look dark or yellow they may need NonyX Nail Gel. NonyX Gel contains naturally-derived ethanoic acid to remove keratin debris buildup from under the nail. With regular use, your nails are clear and healthy-looking – or your money back. Diabetic-friendly NonyX Nail gel is used by podiatrists and can be found in the footcare aisle of your favorite pharmacy or mass retail store. Detailed Description: * Contains patented, naturally-derived ethanoic acid * Topical * Effective * Clear and easy-to-use * All natural * Money-back guarantee * Diabetic-friendly * One 4 oz. bottle is a 2-3 month supply * Made in the USA * NOT TESTED ON ANIMALS FAQ Q: What are the ingredients? A: Deionized Water, Ethanoic Acid, Xanthan Gum, Fragrance

Aromatic Carboxylic Acids Benzoic acid is the aromatic carboxylic acid. locates substituents by numbering the ring from carbon 1 in the carboxyl group. 3,4-Dichlorobenzoic Acid Benzoic Acid Para-Aminobenzoic Acid

Properties of Carboxylic Acids 11 11

Polarity of Carboxylic Acids are strongly polar. have two polar groups: hydroxyl (−OH) and carbonyl (C=O). 12 12

Comparison of Boiling Points Compound Molar Mass Boiling Point 58 49 °C 60 97 °C 60 118 °C 13 13

Solubility in Water Carboxylic acids: form hydrogen bonds with many water molecules. with 1-4 carbon atoms are very soluble in water. Water molecules 14 14

Acidity of Carboxylic Acids are weak acids. ionize in water to produce carboxylate ions and hydronium ions. 15 15

Neutralization of Carboxylic Acids Carboxylic acid salts are a product of the neutralization of a carboxylic acid with a strong base. CH3—COOH + NaOH CH3—COO– Na+ + H2O acetic acid sodium acetate (carboxylic acid salt) are used as preservatives and flavor enhancers. 16 16

Monosodium glutamate (MSG, also known as sodium glutamate)

Esters 18 18

Esters In an ester, the H in the carboxyl group is replaced with an alkyl group. ester group 19 19

Esterification Esterification is the reaction of a carboxylic acid and alcohol in the presence of an acid catalyst to produce an ester. Ethyl acetate (an ester) 20 20

Ester Products Aspirin is used to relieve pain and reduce inflammation. is an ester of salicylic acid and acetic acid. Oil of wintergreen is used to soothe sore muscles. is an ester of salicylic acid and methanol. 21 21

Naming Esters -optional The name of an ester contains the names of the alkyl group from the alcohol. the carbon chain from the acid with –ate ending. methyl ethanoate (acetate) IUPAC: methyl ethanoate common: methyl acetate 22 22

Esters in Plants Esters give pleasant fragrances and flavors to many fruits and flowers. 23 23

Base Hydrolysis (Saponification) Base hydrolysis or saponification, is the reaction of an ester with a strong base. produces the salt of the carboxylic acid and an alcohol. O || CH3—C—O—CH2—CH3 + NaOH  CH3—C—O– Na+ + HO—CH2—CH3 salt of carboxylic acid alcohol 24 24

Base Hydrolysis of Fatty Acids Produces Soaps 25 25

Cleaning Action of Soap A soap contains a nonpolar end that dissolves in nonpolar fats and oils, and a polar end that dissolves in water. forms groups of soap molecules called micelles that dissolve in water and are washed away. 26 26

Amines 27 27

Amines Amines are derivatives of ammonia, NH3. contain N attached to one or more alkyl or aromatic groups. N H 2 28

Naming Amines Simple amines are named as alkylamines. list the names of the alkyl groups bonded to the N atom in alphabetical order in front of amine. CH3—CH2—NH2 Ethylamine CH3—NH—CH3 Dimethylamine CH3 | CH3—N—CH2—CH3 Ethyldimethylamine 29 29

Aromatic Amines The amine of benzene is named aniline. Alkyl groups on the N use the prefix N- with alkyl name. aniline 3-chloroaniline N-methylaniline meta-chloroaniline 30 30

Hydrogen Bonding for Amines The N−H bond provides hydrogen bonding in 1°and 2° amines, but not in 3° amines. is not as polar as the O-H bonds in alcohols. 31 31

Solubility in Water Amines with 1-6 carbon atoms are soluble in water. form hydrogen bonds with the polar O-H bond in water. Copyright © 2009 by Pearson Education, Inc. 32 32

Amines React as Bases Like ammonia, amines are weak bases in water. NH3 + H2O NH4+ + OH– ammonium hydroxide CH3—NH2 + H2O CH3—NH3+ + OH– methylammonium hydroxide 33 33

Neutralization Forms Amine Salts An amine salt forms when an amine is neutralized by acid. is named by replacing the amine part of the name with ammonium, followed by the name of the negative ion. CH3—NH2 + HCl CH3—NH3+ Cl– methylamine methylammonium chloride 34 34

Properties of Amine Salts Amine salts are solids at room temperature. soluble in water and body fluids. the form used for drugs. Ephedrine hydrochloride Ephedrine HCl Sudafed Diphenhydramine hydrochloride Diphenhydramine HCl Benadryl 35 35

Alkaloids Alkaloids are physiologically active nitrogen-containing compounds. obtained from plants. used as anesthetics, antidepressants, and in stimulants such as caffeine. often addictive. 36 36

Cocaine Cocaine (from coca leaves ) is sold illegally as the amine salt. reacted with NaOH to produce the free amine form known as “crack.” Cocaine hydrochloride Cocaine (free base) 37 37

Caffeine Caffeine is a stimulant of the central nervous system. is found in coffee beans, tea, chocolate, and soft drinks. Caffeine 38 38

Nicotine Nicotine increases the adrenaline level in the blood. causes addiction to tobacco. N C H 3 39

Morphine and Codeine Morphine and codeine are alkaloids. obtained from the oriental poppy plant. used as painkillers. modified to make heroin. Morphine Codeine 40 40

Amides 41 41

Amides In amides, an amino group(–NH2) replaces the –OH group of carboxylic acids. 42 42

Aromatic Amide The aromatic amine is benzamide. Benzamide 43 43

Some Amides in Health and Medicine Urea is the end product of protein metabolism. Saccharin is an artificial sweetener. Some amides such as phenobarbital, NembutalTM and SeconalTM are barbiturates. Acetaminophen is used to reduce fever and pain. 44 44

Some Amides in Health and Medicine 45 45

Physical Properties of Amides that are primary (−NH2) or secondary (−NH−) form hydrogen bonds. that are primary have higher melting points than secondary. that are tertiary (no H on N) do not form hydrogen bonds and have lower melting points. all form hydrogen bonds with water. with 1-5 carbon atoms are soluble in water. 46 46

Hydrogen Bonding of Amides || CH3—C—N—H | H Hydrogen bonding occurs between primary amides. H 47 47

The End

End of Chapter Learning Checks Try these after you have reviewed the chapter

Learning Check What primary alcohol can be oxidized to form pentanoic acid? 50

Learning Check Answers What primary alcohol can be oxidized to form pentanoic acid? 1-Pentanol is a primary alcohol that oxidizes to pentanoic acid. 51

Learning Check Write formulas for 3-chloro-4-methylhexanoic acid and α-aminobutyric acid. 52

Learning Check Answers Write formulas for 3-chloro-4-methylhexanoic acid and α-aminobutyric acid. 53

Learning Check Show the organic product for the following reaction. 54

Learning Check Answers Show the organic product for the following reaction. Esterification reaction to form an ester. 55 55

Learning Check Give IUPAC and common names for the following esters. 56 56

Learning Check Answers Give IUPAC and common names for the following esters. 57 57

Learning Check Classify the following amines as 1o, 2o or 3o. 58 58

Learning Check Answers Classify the following amines as 1o, 2o or 3o. 59 59

Learning Check Give the common name for the following amine. 60 60

Learning Check Answers Give the common name for the following amine. 61 61