oh – c – ch 2 – c – ch 2 – c – oh o║o║ o ║ ho – c o║o║ oh

CITRIC ACID

OH – C – CH2 – C – CH2 – C – OH

O║

O ║HO – C

O║

OH

CITRIC ACID

2 – hydroxy – 1,2,3 – propanetricarboxylic acid

CARBOXYLIC ACID

DEFINITION

Carboxylic acids are organic acids characterized by the presence of a CARBOXYL GROUP, which has the formula -C(=O)OH, usually written -COOH or -CO2H.

SYNTHETIC

OXIDATION of ALDEHYDE gen.

formula1ᵒ Alcohol -----→ ALDEHYDE +

H2OKMnO4

K2Cr2O7

(O)

CARBOXYLIC ACID

EXAMPLE

CH3 – CH2 – OH K2Cr2O7

(O)CH3 – C – H + H2O

O║

(O)

CH3 – C – OH

O║

ETHANOIC ACID

ETHANAL

NATURAL

H – C – OH

O║

FORMIC ACID

methanoic acid

HO – C – CH2 – C – OH

O║

O║

MALONIC/MALIC ACID

propanedioic acid

RHUBARB

HO – C – C – OH

O║

O║

OXALIC ACID

ethanedioic acid

CH3 – (CH2)18 – C – OH

O║

ARACHIDIC ACID

ICOSANOIC acid

OH – C – CH2 – C – CH2 – C – OH

OH

O ║HO – C

O║

O║

CITRIC ACID

2 – hydroxy – 1,2,3 – propanetricarboxylic acid

CH3 – (CH2)7 – CH=CH – (CH2)7 – C – OH

O║

OLEIC ACID

OLIVES

LAUREL LEAVES

CH3 – (CH2)10 – C – OH

O║

LAURIC ACID

DODECANOIC acid

Human & Animal FATS

CH3 – (CH2)16 – C – OH

O║

STEARIC ACID

OCTADECANOIC acid

USES

CH3 – C – OH

O║

ACETIC ACID

ethanoic acid

CH3 – CH – C – OH

O║

OH

LACTIC ACID

2 - hydroxypropanoi

c acid

CH3 – (CH2)2 – C – OH

O║

BUTYRIC ACID

butanoic acid

CH3 – (CH2)14 – C – OH

O║

PALMITIC ACID

hexadecanoic acid

NOMENCLATURE

A carboxylic acid is named in the IUPAC system by replacing the –e of the alkane name by Functional group suffix = -oic acid.

The carboxyl carbon is designated as number # 1, and other substituents are located and named accordingly.

However, common names derived from their natural source are used extensively for most carboxylic acid, and the greek letters alpha, beta, gamma and delta are used to show the location of side groups.

IUPAC RULES

Formula Common Name Source IUPAC

NameMelting Point

Boiling Point

HCO2H formic acid ants (L. formica) methanoic acid 8.4 ºC 101 ºC

CH3CO2H acetic acid vinegar (L. acetum)

ethanoic acid 16.6 ºC 118 ºC

CH3CH2CO2Hpropionic

acidmilk (Gk. protus

prion)propanoic

acid -20.8 ºC 141 ºC

CH3(CH2)2CO2H butyric acid butter (L. butyrum)

butanoic acid -5.5 ºC 164 ºC

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

CH3(CH2)4CO2H caproic acid goats (L. caper) hexanoic acid -4.0 ºC 205 ºC

CH3(CH2)5CO2H enanthic acid

vines (Gk. oenanthe)

heptanoic acid -7.5 ºC 223 ºC

CH3(CH2)6CO2H caprylic acid goats (L. caper) octanoic acid 16.3 ºC 239 ºC

CH3(CH2)7CO2H pelargonic acid

pelargonium (an herb)

nonanoic acid 12.0 ºC 253 ºC

CH3(CH2)8CO2H capric acid goats (L. caper) decanoic acid 31.0 ºC 219 ºC

EXAMPLES

1009080706050403020100

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CH3 – (CH2)4 – C – OH

O║

IUPAC

COMMON

HEXANOIC ACID

CAPROIC ACID

1009080706050403020100

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IUPAC

COMMON

2,2 dihydroxypentanoic ACID

α,α - dihydroxyvalericACID

CH3 – (CH2)2 – C – C – OH

O║

OH

OH

1009080706050403020100

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HO – C – CH – C – CH – CH3

CH2 – CH3

NO2

O║

O║

IUPAC

4 – methyl – 2 – nitro – 3 – oxohexanoic ACID

1009080706050403020100

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CH3 – (CH2)2 – C – CH – C – (CH2)2 – C – OH

NO2

CH3HO O║

O║

COMMON NAME

ε – hydroxy – δ – methyl – ε – nitro – γ – oxopelargonic acid

1009080706050403020100

Give D’ IUPAC name of D’ CARBOXYLIC structure

CH3 – (CH2)2 – C – CH2 – C – CH2 – CH3

CH2 – CH3

HO – C – 2HC (CH2)2 – CH3

CH3 – CH2

O║

IUPAC NAME

3,5,5 – triethyl – 3 – propyloctanoic acid

What if there’s a DOUBLE or TRIPLE bond in a structure?

EXAMPLES

CH3 – C ≡ C – C – OH

O║

2 – butynecarboxylic acid

O║C – OH

3 – cyclohexenecarboxylic acid

1009080706050403020100

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HO – C – CH – CH2 – C ≡ C – C – CH3

CH3 – (CH2)2

CH2 – CH3 O║

6 – ethyl – 6 – methyl – 2 – phenyl – 4 – nonynecarboxylic acid

1009080706050403020100

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CH2

O║C – OH

HO

5 – benzyl – 4 – cyclohexyl – 3 – hydroxy – 2 – cyclohexene carboxylic acid

1009080706050403020100

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O║C – OH

CH3 – (CH2)4

4 – pentyl – 2 – cyclopentynecarboxylic acid

1009080706050403020100

Give D’ IUPAC name of D’ CARBOXYLIC structure

CH3 – CH ═ CH – CH2 – C ≡ C – C – OH

O║

5 – hepten – 2 – ynecarboxylic acid

What if there are MULTIPLE CARBOXY in a structure?

OH – C – CH2 – CH2 – C – OH

O║

O║

butanedioic acid Succinic acid

pentanedioic acid Glutaric acid

OH – C – (CH2)3 – C – OH

O║

O║

1009080706050403020100

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OH – C – (CH2)4 – C – OH

O║

O║

hexanedioic acid

Adipic acid

1009080706050403020100

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OH – C – CH2 – C – CH2 – C – OH

O║

O║

OH

O ║HO – C

2 – hydroxy – 1,2,3 – propanetricarboxylic acid

CITRIC ACID

1009080706050403020100

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O ║HO – C

O ║HO – C

O

║

HO

– C

3HC

4 – methyl – 1,2,3 – cyclobutanetricarboxylic acid

What if a CARBOXY group is bound to a benzene structure?

O ║ C – OH

benzoic acid

1009080706050403020100

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Cl

O ║ C – OH Br

3 – bromo – 5 - chlorobenzoic acid

1009080706050403020100

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O

║ C

– OH

NO2

4 – nitro – 2,6 – diphenylbenzoic acid

1009080706050403020100

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OH

O ║ C – OH

2 – hydroxybenzoic acid

SALICYLIC ACID

O – hydroxybenzoic acid

1009080706050403020100

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O ║ C – OH H2N

4 – aminobenzoic acid

p – aminobenzoic acid

PABA

PHYSICAL

Properties

Carboxylic acids are POLAR, and form HYDROGEN BONDS with each other.

C.A. low MW r LIQUID at room temperature w/ sharp unpleasant ODOR.

HIGH temperatures, in vapor phase C.A. usually exist as DIMERIC pairs. LOWER C.A.(1 to 4 carbons) are MISCIBLE with

water, whereas HIGHER carboxylic acids are very much less-soluble due to the increasing HYDROPHOBIC nature of the alkyl chain.

They tend to be rather SOLUBLE in less-polar solvents such as ETHERS and ALCOHOLS.

ONLY ONE OF ITS KIND

Some KINDA CarboxylicCOMMON BOILING °C MELTING °C SOLUBILITY

Formic acid 101 8 infinite

Acetic acid 118 17 Infinite

Propionic acid 141 - 21 infinite

Butyric acid 164 - 5 infinite

Valeric acid 186 - 34 5

Caproic acid 205 - 3 1

Caprylic acid 239 17 insoluble

Capric acid 270 32 insoluble

Lauric acid 299 44 insoluble

Myristic acid decomposes 58 insoluble

Palmitic acid decomposes 63 insoluble

Stearic acid decomposes 71 insoluble

CLASS COMPOUND WEIGHT BOILING

Alkane pentane 72 35 °CEther Diethyl

ether74 35 °C

Aldehyde butanal 72 76 °C

Alcohol 1 - butanol 74 118 °C

Carboxylic acid

Propanoic acid

74 141 °C

Table of Comparison

CHEMICAL

Properties

R EAC T I O N

MEC HAI S M

R E A C T I O N

N

M E C H A N I S M

A step by step description of how a chemical reaction occurs.

NO I TAZI LART U EN

N E U T R A L I Z A T I ONA reaction that involves acids and bases.

IONIZ A T I O N

I ON I Z A T I ONA reaction that deals with cations & anions.

ES T ER IF I CA T IO NA process of forming an ester.

E S T E R I F I C A T I ON

E ST E RSAn organic compound.

E S T E R S

IONIZATIONGEN. FORMULA

Carboxylic acid + Water ↔ Carboxylate ion + Hydronium ion

Example

CH3 – C – O – H + H2O

O║

Acetic acid Acetate ion

CH3 – C – O ־ + H3O +

O║hydronium ion

Ethanoate ion

Examples

O║C – O – H + H2O

O║C – O ־+ H3O +

Benzoic acid Benzoate ion

CH3 – (CH2)4 – C – O – H

O║

+ H2O

Caproic acid

CH3 – (CH2)4 – C – O ־

O║

+ H3O +

Caproate ion

hydronium ion

hydronium ion

Hexanoate ion

NEUTRALIZATIONGEN. FORMULA

Carboxylic acid + Base → Carboxylate salt + Water

Example

CH3 – C – O – H + K – OH

O║

Acetic acid

CH3 – C – O ־ K+ + H2O

O║

Potassium acetate

Potassium ethanoate

Examples

CH3 – (CH2)3 – C – O – H

O║

+ Li – OH

Valeric acid Lithium valerate

Benzoic acid

O║C – O – H + Na – OH

O║C – O ־Na++ H2O

Sodium benzoate

Lithium pentanoate

CH3 – (CH2)3 – C – O ־Li+ + H2O

O║

ESTERIFICATIONGEN. FORMULA

Carboxylic acid + Alcohol → ESTER + WaterH+/ heat

Example

CH3 – C – OH + H – O – CH3

O║

Acetic acid

H+/ heatCH3 – C – O – CH3 + H2O

O║

methyl acetatemethanol

methyl ethanoate

Example

CH3 – (CH2)2 – C – OH

O║

+ H – O – CH2 – CH3

Butanoic acid

H+/ heat

ethyl alcohol

CH3 – (CH2)2 – C – O – CH2 – CH3

O║

+ H2O

ethyl butanoate

ethyl butyrate

ExampleO║C – OH

OH

Salicylic acid

+ H – O – CH3

methyl alcohol

H+/ heat

O║C – O – CH3

OH

+ H2O

methyl salicylate

EXAMPLES

181716000102030405060708091011121314152019Do a sequence of reaction to produce methyl butyrate

an apple flavor, used in food & cosmetic industry.

CH3 – (CH2)2 – C – OH

O║

+ H – O – CH3 H+/ heat

butanoic acidmethyl alcohol

CH3 – (CH2)2 – C – O – CH3

O║

+ H2O

methyl butyratemethyl butanoate

181716000102030405060708091011121314152019Do a sequence of reaction to dissociate

ENANTHIC ACID.

CH3 – (CH2)5 – C – O – H

O║

+ H2O

enanthic acid

CH3 – (CH2)5 – C – O ־

O║

+ H3O+

enanthate ionheptanoate ion

hydronium ion

181716000102030405060708091011121314152019Do a sequence of reaction to produce Calcium propanoatea carboxylic acid salt, used commercially as preservative

in bread, cakes & cheese .

CH3 – CH2 – C – O – H

O║

propanoic acid

+ Ca – OH

Calcium hydroxide

CH3 – CH2 – C – O־ Ca+

O║

+ H2O

Calcium propanoateCalcium propionate

181716000102030405060708091011121314152019Do a sequence of reaction to produce octyl acetate

an orange flavor, used in food & pharmaceutical industry.

CH3 – C – OH

O║

+ H – O – (CH2)7 – CH3

ethanoic acid octyl alcohol

H+/ heat

CH3 – C – O – (CH2)7 – CH3

O║

+ H2O

octyl acetate octyl ethanoate

181716000102030405060708091011121314152019Do a sequence of reaction to dissociate

DECANOIC ACID.

CH3 – (CH2)8 – C – O – H

O║

+ H2O

capric acid

CH3 – (CH2)8 – C – O ־

O║

+ H3O+

caprate ion decanoate ion

hydronium ion

181716000102030405060708091011121314152019Do a sequence of reaction to produce Sodium Stearate

a long chain carboxylic acid salt, used commercially as Surfactant for Soaps .

CH3 – (CH2)16 – C – O – H

O║

+ Na – OH

stearic acidSodium hydroxide

CH3 – (CH2)16 – C – O – Na

O║

+ H2O

Sodium StearateSodium octadecanoate

What are organic compound ESTERS?

Give some examples of ESTERS?

Cite some industrial applications of ESTERS.

References: All organic chemistry book will do.

Assignments

- FIN -