2 Carboxylic Acids O 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.OCH3 — C—OH hydroxyl group or CH3COOHcarbonyl group
3 Models of Carboxylic Acids The three-dimensional models show the geometry of atoms in carboxylic acid molecules.
4 IUPAC Names The IUPAC names of carboxylic acids: Replace the -e in the alkane name with -oic acid.CH methane HCOOH methanoic acidCH3—CH3 ethane CH3—COOH ethanoic acidNumber substituents from the carboxyl carbon 1.CH O| ║CH3—CH—CH2—C—OH3-methylbutanoic acid
7 Aromatic Carboxylic Acids Benzoic acidis the aromatic carboxylic acid.locates substituents by numbering the ring from carbon 1 in the carboxyl group.benzoic acid3-chlorobenzoic acid aminobenzoic acid
8 Learning Check Give the IUPAC names of each compound. A. CH3─CH2─COOH |B. CH3─CH─CH2─COOHC.
9 Solution A. CH3─CH2─COOH propanoic acid CH3 | B. CH3─CH─CH2─COOH 3-methylbutanoic acidC bromobenzoic acid
11 Polarity of Carboxylic Acids are strongly polar.have two polar groups:hydroxyl (−OH) andcarbonyl (C=O).
12 Polarity of Carboxylic Acids form dimers in which hydrogen bonds form between two carboxyl groups.O H—O|| |CH3—C C—CH3| ||O—H OA dimer of acetic acidhave higher boiling points than alcohols, ketones, and aldehydes of similar mass.
13 Comparison of Boiling Points Compound Molar Mass Boiling PointO║CH3−CH2−C−H °CCH3−CH2−CH2−OH °CCH3−C−OH °C
14 Solubility in Water Carboxylic acids: form hydrogen bonds with many water molecules.with 1-4 carbon atoms are very soluble in water.Water molecules
16 Acidity of Carboxylic Acids are weak acids.ionize in water to produce carboxylate ionsand hydronium ions.O O║ ║CH3−C−OH + H2O CH3−C−O– + H3O+
17 Neutralization of Carboxylic Acids Carboxylic acid saltsare a product of the neutralization of a carboxylic acid with a strong base.CH3—COOH + NaOH CH3—COO– Na+ + H2Oacetic acid sodium acetate(carboxylic acid salt)are used as preservatives and flavor enhancers.
18 Learning CheckWrite the equation for the reaction of propanoic acid withA. waterB. KOH
19 Solution Write the equation for the reaction of propanoic acid with A. waterCH3—CH2—COOH + H2O CH3—CH2—COO– + H3O+B. KOHCH3—CH2—COOH + KOH CH3—CH2—COO– K+ + H2O
21 Esters In an ester, the H in the carboxyl group is replaced with an alkyl group.OCH3 — C—O —CH3ester group
22 EsterificationEsterification is the reaction of a carboxylic acid and alcohol in the presence of an acid catalyst to produce an ester.O H+CH3—C—OH + H—O—CH2—CH3CH3—C—O—CH2—CH H2Oethyl acetate (an ester)
23 Learning CheckWrite the equation for the reaction of propanoic acid and methanol in the presence of an acid catalyst.
24 Solution O H+ CH3—CH2—C—OH + H—O—CH3 propanoic acid methanol Write the equation for the reaction of propanoic acid and methanol in the presence of an acid catalyst.O H+CH3—CH2—C—OH + H—O—CH3propanoic acid methanolCH3—CH2—C—O—CH H2O
25 Ester Products Aspirin is used to relieve pain and reduce inflammation.is an ester of salicylic acid and acetic acid.Oil of wintergreenis used to soothe sore muscles.is an ester of salicylic acid and methanol.
26 Naming Esters 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)OCH3— O—C —CH3IUPAC: methyl ethanoatecommon: methyl acetate
28 Learning CheckGive the IUPAC and common names of the following compound, which is responsible for the flavor and odor of pears.OCH3 — C—O—CH2—CH2—CH3
29 SolutionGive the IUPAC and common names of the following compound, which is responsible for the flavor and odor of pears.from 1-propanolOCH3—C—O—CH2—CH2—CH3Propyl ethanoate (IUPAC)Propyl acetate (common)
30 Learning Check Draw the structure of the following compounds. A. 3-bromobutanoic acidB. ethyl propionoate
31 Solution A. 3-bromobutanoic acid Br | CH3—CH—CH2—COOH B. ethyl propionoateOCH3—CH2 —C—O—CH2—CH3
32 Acid Hydrolysis of Esters In acid hydrolysisan ester reacts with water to produce a carboxylic acid and an alcohol.an acid catalyst is required.O H+H—C—O—CH2—CH H2OH—C—OH + H—O—CH2—CH3
33 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—CH NaOH CH3—C—O– Na+ + HO—CH2—CH3salt of carboxylic acid alcohol
35 Cleaning Action of Soap A soapcontains 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.
36 Learning Check A. water and an acid catalyst. B. KOH. Write the organic products when methyl acetate reacts withA. water and an acid catalyst.B. KOH.
37 Solution A. water and an acid catalyst. O CH3—C—OH + HO—CH3 B. KOH. Write the organic products when methyl acetate reacts withA. water and an acid catalyst.OCH3—C—OH HO—CH3B. KOH.CH3—C—O– K HO—CH3
38 Chapter 13 Carboxylic Acids, Ester, Amines, and Amides 13.4Amines
39 Amines Amines are derivatives of ammonia, NH3. contain N attached to one or more alkyl or aromatic groups.CH3 CH3 CH3—NH2 CH3—NH CH3—N—CH3NH2
40 Classification of Amines Amines are classified as primary, secondary, or tertiary.In a primary (1°) amine, one carbon group is bonded to the nitrogen atom.A secondary (2°) amine has two carbon groups bonded to the nitrogen atom.A tertiary (3°) amine has three carbon groups bonded to the nitrogen atom.H CH CH3| | |CH3—N—H CH3—N—H CH3—N—CH31° ° °
42 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 ethylamineCH3—NH—CH3 dimethylamineCH3|CH3—N—CH2—CH3 ethyldimethylamine
43 Learning Check Give the common name and classify as primary, secondary, or tertiary.A. CH3—CH2—CH2—NH2CH3|B. CH3—CH2—N—CH3
44 Solution A. CH3—CH2—CH2—NH2 propylamine, 1° CH3 | B. CH3—CH2—N—CH3 ethyldimethylamine, 3°
45 Aromatic Amines The amine of benzene is named aniline. Alkyl groups on the N use the prefix N- with alkyl name.aniline chloroaniline N-methylaniline
46 Learning Check Give the common name of each compound. A. CH3—NH—CH2—CH3CH3|B. CH3—CH2—N—CH2—CH3C.
47 Solution A. CH3—NH—CH2—CH3 ethylmethylamine CH3 | B. CH3—CH2—N—CH2—CH3 diethylmethylamineC.aniline
48 Hydrogen Bonding for Amines The N−H bondprovides hydrogen bonding in 1°and 2° amines, but not in 3° amines.is not as polar as the O-H bonds in alcohols.
49 Solubility in Water Amines with 1-5 carbon atoms are soluble in water. form hydrogen bonds with the polar O-H bond in water.
50 Learning Check Consider the following compounds. 1) CH3—CH2—CH2—NH2 2) CH3—CH2—NH—CH33) CH3—CH2—CH2—CH3A. Which compound has the highest boiling point?B. Which compound is soluble in water?
51 Solution Consider the following compounds. 1) CH3—CH2—CH2—NH2 2) CH3—CH2—NH—CH33) CH3—CH2—CH2—CH3A. Which compound has the highest boiling point?1) CH3—CH2—CH2—NH2B. Which compound is soluble in water?
52 Amines React as Bases Like ammonia, amines are weak bases in water. NH H2O NH OH–ammonium hydroxideCH3—NH H2O CH3—NH OH–methylammonium hydroxide
53 Neutralization forms Amine Salts An amine saltforms 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
54 Properties of Amine Salts Amine salts aresolids at room temperature.soluble in water and body fluids.the form used for drugs.
55 Alkaloids Alkaloids are physiologically active nitrogen-containing compounds.obtained from plants.used as anesthetics, antidepressants, and in stimulants such as caffeine.often addictive.
56 Cocaine Cocaine is sold illegally as the amine salt. reacted with NaOH to produce the free amine form known as “crack.”
57 Caffeine Caffeine is a stimulant of the central nervous system. is found in coffee beans, tea, chocolate, and soft drinks.
58 Nicotine Nicotine increases the adrenaline level in the blood. causes addiction to tobacco.NCH3
59 Morphine and Codeine Morphine and codeine are alkaloids. obtained from the oriental poppy plant.used as painkillers.modified to make heroin.
60 Learning Check Write the structural formula for A methylpropylamine B chloroaniline
64 Aromatic AmideThe aromatic amine is benzamide.benzamide
65 Preparation of Amides Amides are produced by reacting a carboxylic acid with ammoniaor an amine (1° or 2°).using heat.O O Heat CH3—C—OH + NH CH3—C—NH2 + H2OO O Heat CH3—C—OH + CH3—NH CH3—C—NH—CH3 + H2O
66 Naming Amides Amides are named as alkanamides. IUPAC replaces –oic acid ending with –amide.Common names replace -ic acid ending with –amide.O Methanamide (IUPAC)H—C—NH2 Formamide (common) Propanamide (IUPAC)CH3—CH2—C—NH2 Propionamide (common)
67 Naming Amides with N Groups An alkyl group bonded to the N atom is named asN-alkyl in front of the amide name.O H │CH3 —C—N—CH N-methylethanamide (IUPAC)N-methylacetamide (common)CH3—CH2 —C—N—CH2—CH3N-ethylpropanamide (IUPAC)N-ethylpropionamide (common)
68 Learning Check Give the IUPAC and common names for the following. O A. CH3–CH2–CH2–C–NH2O H │B. CH3–C–N–CH2–CH3
69 Solution O A. CH3–CH2–CH2–C–NH2 butanamide; butryamide O H │ │B. CH3–C–N–CH2–CH3N-ethylethanamide; N-ethylacetamide
70 Learning Check Draw the structures of A. pentanamide. B. N-methylbutyramide.
71 Solution O CH3–CH2–CH2–CH2–C–NH2 B. N-methylbutyramide A. pentanamideOCH3–CH2–CH2–CH2–C–NH2B. N-methylbutyramideCH3–CH2–CH2–C–NH–CH3
72 Some Amides in Health and Medicine Urea is the end product of protein metabolism.Saccharin is an artificial sweetener.Some amides such as phenobarbital, Nembutal and Seconal are barbiturates.Acetaminophen is used to reduce fever and pain.
74 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.