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AnnouncementsAnnouncements & Agenda& Agenda (04/02/07)(04/02/07)

Pop Quiz Right Now!Pop Quiz Right Now!

Quiz on Wednesday (Chirality & Ch 13)Quiz on Wednesday (Chirality & Ch 13)

Will hand HW practice in labWill hand HW practice in lab

TodayToday Esters (13.3)Esters (13.3) Amines (13.4)Amines (13.4) Amides (13.5)Amides (13.5)

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Last Time: Drawing Fischer ProjectionsLast Time: Drawing Fischer Projections

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Last Time: Carboxylic AcidsLast Time: Carboxylic Acids

Carboxylic acids Carboxylic acids • are weak acids.are weak acids.• ionize in water to produce carboxylate ionize in water to produce carboxylate

ions and hydronium ions.ions and hydronium ions.

O O OO ║║ ║║

CHCH33−−CC−−OH + HOH + H22OO CH CH33−−CC−−OO– – + +

HH33OO++

~1%~1%

Also: Neutralization Reactions! Esterification!Also: Neutralization Reactions! Esterification!

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Ester ProductsEster Products

AspirinAspirin• is used to relieve pain and is used to relieve pain and

reduce inflammation.reduce inflammation.• is an ester of salicylic acid is an ester of salicylic acid

and acetic acid.and acetic acid.

Oil of wintergreenOil of wintergreen• is used to soothe sore is used to soothe sore

muscles. muscles. • is an ester of salicylic acid is an ester of salicylic acid

and methanol. and methanol.

CH3

O

CO

OH

O

C

OH

CH3O

O

C

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Naming EstersNaming Esters

The name of an ester contains the names ofThe name of an ester contains the names of

• the the alkyl groupalkyl group from the alcohol. from the alcohol.

• the carbon chain from the acid with the carbon chain from the acid with ––ateate ending. ending.

methylmethyl ethanoate (acetate)ethanoate (acetate)

OO

CHCH33—— OO——CC —CH—CH33

IUPAC: IUPAC: methylmethyl ethanoateethanoate

common:common: methylmethyl acetateacetate

-oate: means -oate: means ester presentester present

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Esters in PlantsEsters in Plants

Esters give flowers and fruits their Esters give flowers and fruits their pleasant fragrances and flavors.pleasant fragrances and flavors.

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• an ester reacts with water to produce a an ester reacts with water to produce a carboxylic acid and an alcohol.carboxylic acid and an alcohol.

• an acid catalyst is required. an acid catalyst is required. OO

HH++

HH——CC——OO——CHCH22——CHCH3 3 ++ HH22OO

OO HH——CC——OHOH + + HH——OO——CHCH22——CHCH33

Acid Acid HydrolysisHydrolysis of Esters of Esters

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• is the reaction of an ester with a strong base. is the reaction of an ester with a strong base.

• produces the salt of the carboxylic acid and an produces the salt of the carboxylic acid and an alcohol.alcohol. OO

|||| CHCH33——CC—O—O——CHCH22——CHCH3 3 ++ NaOHNaOH

OO CHCH33——CC——OO– – NaNa++ + + HHOO——CHCH22——CHCH33

salt of carboxylic acid alcoholsalt of carboxylic acid alcohol

Base Base HydrolysisHydrolysis (Saponification) (Saponification)

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Last Time: Base Last Time: Base HydrolysisHydrolysis of of Triglycerides Make SoapsTriglycerides Make Soaps

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Carboxylic acids with lots of carbons are fatty Carboxylic acids with lots of carbons are fatty acids (usually even #, 10, 12, 14, 16, 18)acids (usually even #, 10, 12, 14, 16, 18)

Sodium salts of fatty acids are soaps.

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Cleaning Action of SoapCleaning Action of Soap

A A soapsoap• contains a nonpolar end contains a nonpolar end

that dissolves in that dissolves in nonpolar fats and oils, nonpolar fats and oils, and a polar end that and a polar end that dissolves in water.dissolves in water.

• forms groups of soap forms groups of soap molecules called molecules called micellesmicelles that dissolve in that dissolve in water and are washed water and are washed away.away.

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Write the organic products when methyl acetate reacts withWrite the organic products when methyl acetate reacts withA. water and an acid catalyst.A. water and an acid catalyst.

OO CHCH33——CC——OH + HOH + HOO——CHCH33

B. KOH.B. KOH. OO

CHCH33——CC——OO– – KK++ + H + HOO——CHCH33

Learning CheckLearning Check

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13.4 Amines (Derivatives of NH13.4 Amines (Derivatives of NH33))Typically 3 kinds:Typically 3 kinds:• Primary (1°) amines:Primary (1°) amines: 1 carbon group is bonded to N 1 carbon group is bonded to N• Secondary (2°) amines:Secondary (2°) amines: 2 carbon groups bonded to N 2 carbon groups bonded to N• Tertiary (3°) amines:Tertiary (3°) amines: 3 carbon groups bonded to N. 3 carbon groups bonded to N.

HH CHCH33 CHCH33 || || || CHCH33—N—H—N—H CHCH33—N—H—N—H CHCH33—N——N—CHCH33

1°1° 2° 2° 3° 3°

Quaternary (4Quaternary (4°) amines also possible (4 C groups attached to °) amines also possible (4 C groups attached to nitrogen atom)nitrogen atom)

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Naming Amines (No need to memorize)Naming Amines (No need to memorize)

• Simple amines are named as Simple amines are named as alkylaminesalkylamines..• Names of alkyl groups bonded to the N atom listed in Names of alkyl groups bonded to the N atom listed in

alphabetical order in front of alphabetical order in front of amineamine..

CHCH33——CHCH22——NHNH2 2 ethylethylamineamine

CHCH33—NH——NH—CHCH33 ddimethylimethylamineamine

CHCH33

||CHCH33—N——N—CHCH22—CH—CH33 ethyldimethylethyldimethylamineamine

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Hydrogen Bonding for AminesHydrogen Bonding for Amines

• N-H bond provides hydrogen bonding in N-H bond provides hydrogen bonding in 1°and 2° amines, but not in 3° amines.1°and 2° amines, but not in 3° amines.

• is not as polar as the O-H bonds in alcohols.is not as polar as the O-H bonds in alcohols.• H-bonding not as good H-bonding not as good

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Solubility in WaterSolubility in Water

• Amines with 1-5 carbon atoms are soluble in water.Amines with 1-5 carbon atoms are soluble in water.

• Form hydrogen bonds with the polar O-H bond in Form hydrogen bonds with the polar O-H bond in water.water.

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Like ammonia, amines are weak bases in water.Like ammonia, amines are weak bases in water.

NHNH33 + H + H22OO NH NH44++ + OH + OH––

ammonium hydroxideammonium hydroxide

CHCH33——NHNH22 + H + H22OO CH CH33——NHNH33++ + OH + OH––

methylammonium hydroxidemethylammonium hydroxide

Amines React as BasesAmines React as Bases

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An An amine saltamine salt

• forms when an amine is forms when an amine is neutralized by acid. neutralized by acid.

CHCH33——NHNH22 + HCl CH + HCl CH33——NHNH33++

ClCl––

methylaminemethylamine

Neutralization forms Amine SaltsNeutralization forms Amine Salts

methylammonium chloridemethylammonium chloride

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OK so far???OK so far???

0%

0%

0% 1.1. YesYes

2.2. NoNo

3.3. Kinda…Kinda…

11 22 33 44 55

2020

Properties of Amine Salts Properties of Amine Salts

• solids at room temperature.solids at room temperature.

• soluble in water and body fluids.soluble in water and body fluids.

• the form used for drugs.the form used for drugs.

• DON’T STINK!DON’T STINK!

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AlkaloidsAlkaloids

• physiologically active physiologically active nitrogen-containing nitrogen-containing compounds.compounds.

• obtained from plants.obtained from plants.

• used as anesthetics, used as anesthetics, antidepressants, and in antidepressants, and in stimulants such as stimulants such as caffeine.caffeine.

• often addictive. often addictive.

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CocaineCocaine• sold illegally as the amine salt.sold illegally as the amine salt.

• reacted with NaOH to produce the free reacted with NaOH to produce the free amine form known as “crack.”amine form known as “crack.”

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CaffeineCaffeine• is a stimulant of the is a stimulant of the

central nervous system central nervous system

Caffeine and NicotineCaffeine and Nicotine

Nicotine• increases adrenaline level in blood

N

CH3

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Morphine and CodeineMorphine and Codeine

• alkaloids.alkaloids.• obtained from the obtained from the

oriental poppy plant.oriental poppy plant.• used as painkillers. used as painkillers. • modified to make modified to make

heroin.heroin.

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• In In amidesamides, an amino group(–NH, an amino group(–NH22) replaces the –OH ) replaces the –OH

group of carboxylic acids.group of carboxylic acids. OO O O |||| ||||

CHCH33——CC——OHOH CHCH33——CC——NHNH22

Amides 13.5Amides 13.5

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Preparation of AmidesPreparation of Amides

Amides are producedAmides are produced• by reacting a carboxylic acid with ammonia by reacting a carboxylic acid with ammonia

or an amine (1or an amine (1° or 2°).° or 2°).• using heat.using heat. OO O O HeatHeat CHCH33——CC——OH +OH + NHNH33 CH CH33—C—C——NHNH22 + H+ H22OO

OO O O Heat Heat CHCH33——CC——OH + OH + CHCH33——NHNH22 CH CH33—C——C—NH—CHNH—CH33 + H+ H22OO

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Some Amides in Health and MedicineSome Amides in Health and Medicine

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Physical Properties of AmidesPhysical Properties of Amides

SIMILAR TO AMINES…SIMILAR TO AMINES…• primary (primary (−−NHNH22) or secondary () or secondary (−−NHNH−−) amides ) amides

form hydrogen bonds.form hydrogen bonds.• primary have higher mp’s than secondary.primary have higher mp’s than secondary.

• tertiary (no H on N) do not form hydrogen bonds & tertiary (no H on N) do not form hydrogen bonds & have lower melting points.have lower melting points.

• all form hydrogen bonds with water.all form hydrogen bonds with water.• with 1-5 carbon atoms are soluble in water.with 1-5 carbon atoms are soluble in water.

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Hydrogen Bonding of AmidesHydrogen Bonding of Amides

O O |||| CHCH33——CC—N—H —N—H || HH Hydrogen bonding occurs Hydrogen bonding occurs

between primary amides.between primary amides. O O ||||

CHCH33——CC—N—H—N—H ||

HH

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Amides undergoAmides undergo• Acid hydrolysisAcid hydrolysis to produce a carboxylic to produce a carboxylic

acid and an ammonium salt.acid and an ammonium salt.

• Base hydrolysisBase hydrolysis to produce the salt of a to produce the salt of a carboxylic acid and an amine or ammonia.carboxylic acid and an amine or ammonia.

• REACTIONS LOOK SIMILAR TO THOSE REACTIONS LOOK SIMILAR TO THOSE OF ESTERS!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!OF ESTERS!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

Hydrolysis of AmidesHydrolysis of AmidesIMPORTANT TO KNOWIMPORTANT TO KNOW

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acid hydrolysisacid hydrolysis OO

|||| OO CH CH33——CC——OH + NHOH + NH44

++ClCl––

|||| HClHCl + H+ H22O O CHCH33——CC—NH—NH22

NaOHNaOH OO ||||

CHCH33——CC——OO– – NaNa++ + NH + NH33

base hydrolysisbase hydrolysis

Hydrolysis ReactionsHydrolysis Reactions