THEME: Structure and chemical THEME: Structure and chemical properties of carboxylic acids. properties of carboxylic acids. Heterofunctional compounds.Heterofunctional compounds.

LECTURELECTURE 22

LecturerLecturer: Yevheniya. B. DmukhalskaYevheniya. B. Dmukhalska

PlanPlan1. Nomenclature of carboxylic acids2. Physical properties of carboxylic acids.3. Classification of carboxylic acids4. Methods of preparation of carboxylic acids5. Chemical properties of carboxylic acids.6. Heterofunctional compounds. 7. Hydroxy-acids, nomenclature, isomerism,

chemical properties and specific reactions for hydroxy-acids.

8. Introduction of optical isomerous. Mirror (optical) isomerism. Asymmetric carbon atom. Properties of enantiomers.

Carboxylic acids Carboxylic acids Carboxylic acids Carboxylic acids are compounds whose are compounds whose characteristic functional group is the carboxyl characteristic functional group is the carboxyl group group -- COOH COOH , example: , example:

Common formula of carboxylic acid: Common formula of carboxylic acid:

Formula Common Name IUPAC Name

HCO2H formic acid methanoic acid

CH3CO2H acetic acid ethanoic acid

CH3CH2CO2H propionic acid propanoic acid

CH3(CH2)2CO2H butyric acid butanoic acid

CH3(CH2)3CO2H valeric acid pentanoic acid

CH3(CH2)4CO2H caproic acid hexanoic acid

CH3(CH2)5CO2H enanthic acid heptanoic acid

CH3(CH2)6CO2H caprylic acid octanoic acid

CH3(CH2)7CO2H pelargonic acid nonanoic acid

CH3(CH2)8CO2H capric acid decanoic acid

Nomenclature of carboxylic acidsNomenclature of carboxylic acids

Classification of carboxylic acids : Classification of carboxylic acids :

1. By the nature of hydrocarbon radical1. By the nature of hydrocarbon radicala) a) saturated acids;saturated acids;

b) b) unsaturated acids unsaturated acids

c) c) aromatic acidaromatic acid

2. By 2. By the number of carboxyl groupsthe number of carboxyl groupsa) monocarboxylic acids;a) monocarboxylic acids;

b) dicarboxylic acids.b) dicarboxylic acids.

Saturated acidsSaturated acidsare acids, which have only simple bonds in are acids, which have only simple bonds in molecule. Example: molecule. Example:

methanoic (formic) acidmethanoic (formic) acid

ethanoic (acetic) acidethanoic (acetic) acid

propanoic (propanoic (propionic acid) acid) acid

stearic acid (octadecanoic acid)

H CO

OH

CH3 CO

OH

CH3 CH2C

O

OH

CH3-(CH2)16-COOH

Unsaturated acidUnsaturated acidis an acid, which has both as simple bonds is an acid, which has both as simple bonds and duble bonds in molecule. Example:and duble bonds in molecule. Example:CHCH22=CH-COOH=CH-COOH

Aromatic Aromatic acidacid

is acid, which contain aromatic ring. is acid, which contain aromatic ring. Example: benzoic acid.Example: benzoic acid.

Monocarboxylic acidMonocarboxylic acid

is acid, which has one carboxylic group in is acid, which has one carboxylic group in molecule. Example: acetic acid, formic molecule. Example: acetic acid, formic acid, buthanic acid.acid, buthanic acid.

Dicarboxylic acidDicarboxylic acid

is acid, which has two carboxylic group in is acid, which has two carboxylic group in molecule. Example: oxalic acid, malonic molecule. Example: oxalic acid, malonic acid.acid.

The names of some saturated monocarboxylic acids

Structural formula Name of nomenclature

trivial substitute rational

formic acid methanoic acid -

acetic acid etanoic acid acetic acid

propionic acid propanoic acid methylacetic acid

oil acid butanoic acid ethylacetic acid

iso oil acid 2-methylpropanoic acid

dimethylacetic acid

valeric acid pentanoic acid propylacetic acid

iso valeric acid 3-methylbutanoic acid

methylethylacetic acid

CH3-(CH2)4-COOH capronic acid hexanoic acid n-butylacetic acid

CH3-(CH2)10-COOH lauric acid dodecanoic acid

CH3-(CH2)12-COOH myristic acid tetradecanoic acid

CH3-(CH2)14-COOH palmitic acid hexadecanoic acid

CH3-(CH2)16-COOH stearic acid octadecanoic acid

CO

OHCH3

CH3 CH CH2

1234

CH3 CH2C

O

OHCH2 CH2

CH3 CH CO

OH

CH3

123

CH3 CH2C

O

OHCH2

CH3 CH2C

O

OH

CH3 CO

OH

H CO

OH

The names of some unsaturated monocarboxylic acids

Structural formula Name of nomenclature

trivial substitute

CHCH22=CH-COOH=CH-COOH acrylic acid propenoic acid

methacrylic acid 2-methylpropenoic acid

CHCH22=CH-CH=CH-CH22-COOH-COOH vinyl acetic acidvinyl acetic acid 3-butenoic acid

crotonic acid trans-2-butenoic acid

iso crotonic acid cus-2-butenoic acidcus-2-butenoic acid

propiolic acid propionoic acid

tetrolic acid 2-butynoic acid

oleic acid cus-9-octadecenoic acid

Linoleic acid cus-9-cus-12-octadecadienoic acid

linolenic acid cus-9-cus-15-octadecatrienoic acid

CH

CCH2 COOH

3

C CCOOH

H

H

CH3

C CH

COOH

H

CH3

CH C COOH

C COOHCCH3

4 3 2 1

CH

CH (CH2)7 CH3

(CH2)7 COOH

CH

CH

(CH2)4CH3

CH2CH

CH (CH2)7 COOH

CH

CH3

CH2

CH2CH

CH CH2

COOH

CHCH

CH (CH2)7

The names of some dicarboxylic acids

Structural formula Name of nomenclature

trivial substituteHOOC-COOH oxalic acid ethandioic acidethandioic acid

HOOC-CH2-COOH malonic acidmalonic acid propandioic acidpropandioic acid

HOOC-CH2-CH2-COOH succinic acid butandioic acidbutandioic acid

HOOC-CH2-CH2-CH2-COOH glutaric acid pentandioic acidpentandioic acid

HOOC-CH2-CH2-CH2-CH2-COOH adypinic acid hexandioic acidhexandioic acid

HOOC-(CH2)5-COOH pimelic acid heptadioic acidheptadioic acid

HOOC-(CH2)6-COOH cork acid octandioic acidoctandioic acid

maleic acidmaleic acid cus-butendioic acidcus-butendioic acid

fumaric acid trans-butendioic acid trans-butendioic acid

phthalic acid 1,2-benzoldicarbonic acid1,2-benzoldicarbonic acid

iso iso phthalic acid 1,3-benzoldicarbonic acid1,3-benzoldicarbonic acid

C C

COOHHOOC

HH

C C

HOOC

HCOOH

H

COOH

COOH

COOH

COOH

Methods of preparation of carboxylic acids.Methods of preparation of carboxylic acids.

1. Oxidation of alkylbenzenes.

2. Oxidation of primary alcohols.

3. Oxidation of aldehydes.

44. Synthesis of carboxylic acids by the hydrolysis of nitriles.. Synthesis of carboxylic acids by the hydrolysis of nitriles.

Properties of Carboxylic AcidsPhysical Properties of Carboxylic Acids

Formula IUPAC Name Melting Point Boiling Point

HCO2Hmethanoic

acid8.4 ºC 101 ºC

CH3CO2H ethanoic acid 16.6 ºC 118 ºC

CH3CH2CO2H propanoic acid -20.8 ºC 141 ºC

CH3(CH2)2CO2H butanoic acid -5.5 ºC 164 ºC

CH3(CH2)3CO2H pentanoic acid -34.5 ºC 186 ºC

CH3(CH2)4CO2H hexanoic acid -4.0 ºC 205 ºC

CH3(CH2)5CO2H heptanoic acid -7.5 ºC 223 ºC

CH3(CH2)6CO2H octanoic acid 16.3 ºC 239 ºC

CH3(CH2)7CO2H nonanoic acid 12.0 ºC 253 ºC

CH3(CH2)8CO2H decanoic acid 31.0 ºC 219 ºC

Solubility of carboxylic acids

Chemical properties of carboxylic acids.Chemical properties of carboxylic acids.

Reduction reaction.

Carboxylic acids are reduced to primary alcohols by the powerful reducing agent lithium aluminum hydride.

Salt formationSalt formation

Magnesium acetate

Calcium acetate

Sodium butanoate

αα-halogenation of carboxylic acids-halogenation of carboxylic acids This method of α bromination of carboxylic acids is called the

Hell–Volhard– Zelinsky reaction.

R-COH

O SOCl2R-C

Cl

O

R1OHR-C

O-R1

O

R1SHR-C

S-R1

O

R-CO

O

ONH3

R-CNH2

O

R-CNR2

O

P2O5

R-CO

O

O

R1OH

R-CO-R1

O

H2O

R1-COONа

R1-C

R2-NH

R1-C

H2O

1

2

3

4

5окрім реакції (3)

H2O

Except reaction 3

Substitution of the Hydroxyl GroupSubstitution of the Hydroxyl Group

1. 1. ESTERIFICATIONESTERIFICATION

This page looks at esterification - mainly the This page looks at esterification - mainly the reaction between alcohols and carboxylic acids reaction between alcohols and carboxylic acids to make esters.to make esters.

2. Formation of acyl chlorides. Formation of acyl chlorides. Thionyl chloride reacts with carboxylic acids to yield acyl chlorides.

RReaction with halo-compoundseaction with halo-compounds::

 

3. 3. Preparation of Acid AnhydridesPreparation of Acid Anhydrides

4. The formation amides.4. The formation amides.

H2C

H2C

C

C

OH

OH

O

O

+ NH3

t

O

O

N H + H2O

succinic acidsukcynimide

Formation of the biuret and a biuret reaction

urea

Decarboxylation of carboxylic acids. The loss of a molecule of carbon dioxide from a carboxylic acid is

known as decarboxylation.

C6H5COOH

benzoic acid

NaOHC6H5COONa + H2O

C2H5OH; H+C6H5 C

O

OC2H5

ethylbenzoath

PCl5C6H5 C

O

Clbenzoilchloride

(CH3CO)2O; H+

C6H5 C

O

OC

O

C6H5

+

+ +

+

H2O

HCl POCl3

CH3COOH2

anhydride of benzoic acid

HOOC CH2 CH2 COOH

succinic acidHOOC CH CH COOH

Br Br-dibromsuccinic acid

HOOC CH CH2 COOHchlorsuccinic acid

H2

Br2

HCl

COOH

CH

CH

COOHbutendioic acid

HOH; H+

[O]

KMnO4

HOOC CH CH2 COOH

malic acid

HOOC CH CH COOH

racemic acid

2, 3

8. Carboxylic acid derivatives.8. Carboxylic acid derivatives.

These classes of compounds are classified as carboxylic acid derivatives. All may be converted to carboxylic acids by hydrolysis.

Functional groups are groups of atoms found within molecules that are involved in the chemical reactions characteristic of those molecules.

There are mono-, poly- and heterofunctional group in the structure of organic compounds:Monofunctional group – contains only 1 functional group.

C2H5—OH

Polyfunctional group – contains several similar functional group.H2C

CH

H2C

OH

OH

OH

Heterofunctional group – contains several different functional group.

Sphingosine

Biological role:Biological role: Heterofunctional compounds are widespread in the Heterofunctional compounds are widespread in the

nature. They are in fruits and vegetable leafs. Also nature. They are in fruits and vegetable leafs. Also they are formed in body. So, the lactic acid is they are formed in body. So, the lactic acid is product of transformation glucose (glycolysis) in product of transformation glucose (glycolysis) in human body. A malic and citric acid formed in a human body. A malic and citric acid formed in a cycle of tricarboxylic acids, which is also known as cycle of tricarboxylic acids, which is also known as citric acid cycle or Krebs' cycle. Hydroxo acids citric acid cycle or Krebs' cycle. Hydroxo acids such as: pyruvic acid, acetoacetic acid, oxaloacetic such as: pyruvic acid, acetoacetic acid, oxaloacetic acid, acid, -ketoglutaric acid are important in -ketoglutaric acid are important in metabolism of carbohydrates.metabolism of carbohydrates.

HydroxyacidsHydroxyacids HydroxyacidsHydroxyacids are the derivatives of carboxyl acids that are the derivatives of carboxyl acids that

contain –OH group (1 or more).contain –OH group (1 or more).

3 2 1CH3C CH

O

OHOH

β α

2-hydroxypropanoic acidα-hydroxypropanoic acid

tartaric acidα,α’-dihydroxysuccinic acid,2,3-dihydroxybutandioic acid,

lactic acid,α- hydroxypropanoic acid,2- hydroxypropanoic acid

malic acid,hydroxysuccinic acidhydroxybutanedioic acid

citric acid,2-hydroxy-1,2,3-propantricarboxylic acid

glycolic acid,hydroxyacetic acid,hydroxyethanoic acid

Methods of preparation of hydroxyacids:1.1. Hydrolysis of α-halogenoacidsHydrolysis of α-halogenoacids

2.2. Oxidations of diols and hydroxyaldehydesOxidations of diols and hydroxyaldehydes

3.3. Hydration of α,β-unsaturated carboxylic acidsHydration of α,β-unsaturated carboxylic acids

4.4. Hydrolysis of hydroxynitriles (cyanohydrins)Hydrolysis of hydroxynitriles (cyanohydrins)

CH3C CH

O

OHCl

NaOHH2O CH3C CH

O

OHOH

NaCl+ + lactic acidlactic acid

CH3C CH

O

HOH

CH2H3C CH

OHOH

CH3C CH

O

OHOH

[O] [O]

CH CO

OHH2O+CH2 CH2C CH2

O

OH

H+

OH

ββ-hydroxypropanoic acid-hydroxypropanoic acid

Physical and chemical properties of

hydroxycarboxylic acid For For physical propertiesphysical properties of hydroxycarboxylic acids are of hydroxycarboxylic acids are

colorless liquids or crystalline substance, soluble in water.colorless liquids or crystalline substance, soluble in water.

Chemical properties:Chemical properties:

Carboxyl group can react forming:Carboxyl group can react forming:

a) salts:a) salts:H2C CH2 C

O

OHOH

NaOH H2C CH2 CO

ONaOH

H2O+ +

sodium sodium ββ-hydroxypropanoic acid-hydroxypropanoic acid

2 H2C CH2 CO

OHOH

2 Na 2 H2C CH2 CO

ONaOH

H2+ +

2 H2C CH2 CO

OHOH

MgO

H2C CH2 CO

OMg

O

CO

H2C CH2

OH

OH

H2O+ +

H2C CH2 CO

OHOH

NaHCO3 H2C CH2 CO

ONaOH

H2CO3

H2O CO2

++

Ester formation:H2C CH2 C

O

OH++

OH

H2OHO CH3 H2C CH2 CO

OOH

CH3

Methyl-Methyl-ββ-hydroxypropanoate-hydroxypropanoate

Methyl-Methyl-ββ-methoxylpropanoat-methoxylpropanoat

ββ-ethanoatepropanoic acid-ethanoatepropanoic acid

c) Amides formation:c) Amides formation:

II. –OH group reaction:II. –OH group reaction:

a) hydrohalogens (HCl, HBr, HI, HF)a) hydrohalogens (HCl, HBr, HI, HF)

b) can oxidize

H2C CH2 CO

OH+NH3+

OH

H2C CH2 CO

NH2OH

H2Ot=200o

amide of amide of ββ-hydroxypropanoic acid-hydroxypropanoic acid

HCl ++ H2OH2C CH2 CO

OHCl

CH2C CH2

O

OHOH

+ H2OCH2C CH2

O

OH

[O]

OH

CHC CH2

O

OHO

ββ-oxopropanoic acid-oxopropanoic acid

lactic acid lactide

Related to heat of:

1. α-hydroxyacids

2. β-hydroxyacids

3. γ-hydroxyacids

H

O

C

O H

C H 3

O

C

H

+

O

O H

CС H 3 С

O H

H

H 2S O 4к .

t

HCOOH CO + H2Oк. Н2SO4, t

Ñ ÑH2COOHHOOCH2C

OH

COOH

H CO

OHC CH2COOH

O

HOOCH2C

C CH3CH3

O

ê. H2SO4 +

CO H2O 2 CO2

t acetidicarbonic acid

Decomposition α-hydroxyacids

Ethanal

formic acid

Phenolacids.Phenolacids.

o-hydroxycinnamic acid salicylic acid,2-hydroxybenzoic acid

4-hydroxybenzoic acid

3,4,5-trihydroxybenzoic acid,gallic acid

PhenolacidsPhenolacids are the derivatives of aromatic carboxyl acids that are the derivatives of aromatic carboxyl acids that contain –OH group (1 or more).contain –OH group (1 or more).

COOH

OH OH

COONa+ CO2+ NaHCO3 + H2O

salicylic acid

Phenolacids are the derivatives of aromatic carboxyl acids that contain –OH group (1 or more).

Decarboxylation

Representatives of hydroxyacids: Lactic acid is a trivial name because

at first it was extracted from milk. It is present in yogurt, sour milk and other milk products. It can form in muscles during hard and prolonged work. Salts of milk acid are used in medicine.

Malic acid. It is present in green apples and

some berries. It takes part in biological processes in human organisms and organisms of other alive creatures. It is used in medicine for synthesis of some medical preparations.

Tartaric acid . It is present in grape. It is used in medicine for synthesis of some

medical preparations.

CH3C CH

O

OHOH

CH2 CO

OHCHC

O

HOOH

CH

CH

C

C

OH

OH

O

OH

O

OH

Citric acidCitric acid . It . It is present in is present in orange, lemon and other orange, lemon and other

citric fruits. It takes citric fruits. It takes part in part in biological biological processes in processes in human human organism.organism.

HO C

CH2

C

CH2OH

O

C

C

O

OH

O

OH

OxoacidsOxoacidsTo oxoacids include aldehydo- and ketonoacids. These compounds include in the structure of the carboxyl group, aldehyde functional group or ketone functional group.

γ-ketovaleric acid,4-oxopentanoic acid,levulinic acid

acetoacetic acid,3-oxobutanoic acid,β-ketobutyric acid

oxalacetic acid,oxobutanedioic acid,ketosuccinic acid

glyoxylic acid,oxoethanoic acid

Pyroracemic (pyruvic) acid,2-oxopropanoic acid

ketoglutaric acid

Chemical properties of oxoacidsChemical properties of oxoacids1.1. Decarboxylation of Decarboxylation of αα-oxoacids-oxoacids

2.2. Decarboxylation of Decarboxylation of ββ-oxoacids-oxoacids

CH3 C

O

COOHconc. H2SO4, t

CH3 C + CO2

O

Hpyroracemic acid acetaldehyd

CH3 C

O

t

acetoacetic acid

CH2 COOH CH3 C CH3

Oacetone

- CO2

Thank you for attention