aldehydes, ketones, and carboxylic acids...carboxylic acids aldehydes, ketones, and carboxylic acids...
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Carbonyl Compounds
ALDEHYDES, KETONES, AND CARBOXYLIC ACIDS - PART I
Used as a solvent, starting material and reagent
Benzaldehyde - Used in perfumery and in dye industries. Acetone and ethyl methyl ketone are common industrial solvents
Acetaldehyde - Used primarily as a starting material in the manufacture of aceticacid, ethyl acetate, vinyl acetate, polymers and drugs
Formaldehyde - Formalin (40%) solution used to preserve biological specimensand to prepare bakelite, urea-formaldehyde glues and other polymeric products
Nomenclature of Carbonyl Group
Structure of Carbonyl Group
Uses of Aldehydes and Ketones
Carbonyl group is a functional group composedof a carbon atom double bonded to an oxygen atom
R H
O
R R
O
Aldehydes Ketones
C
O
C+
O-
Cσ-bondsp 2
sp2 O..
..
C
Л-bondsp 2
sp2 O..
.. C120o
120o
120o
O..
..
Aldehydes
Ketones
HCHOCH3CHO(CH3)2CHCHO
FormaldehydeAcetaldehydeIsobutyraldehyde
MethanalEthanal2-Methylpropanal
3-Methylcyclohexanecarbaldehyde
2-MethoxypropanalPentanalProp-2-enal
Pentan-2-one2,4-Dimethylpentan-3-one
4-Methylpent-3-en-2-one
2-Methylcyclohexanone
Benzene- 1,2-dicarbaldehyde
γ-Methylcyclohexanecarbaldehyde
α-Methylcyclohexanone
α-MethoxypropionaldehydeValeraldehydeAcrolein
Phthaldehyde
m-Bromobenzaldehyde 3-Bromobenzenecarbaldehydeor3-Bromobenzaldehyde
Methyl n-propyl ketoneDiisopropyl ketone
Mesytil oxide
CH3CH(OCH3)CHOCH3CH2CH2CH2CHOCH2=CHCHO
CH3COCH2CH2CH3(CH3)2CHCOCH(CH3)2
(CH3)2C=CHCOCHCH3
Structure Common Name IUPAC Name
CHOH3C
CHO
CHO
O
CH3
CHO
Br
Carboxylic acids
ALDEHYDES, KETONES, AND CARBOXYLIC ACIDS - PART II
• Methanal (HCHO) is a gas at room
temperature
• Ethanal (CH3CHO) is a volatile liquid
• The boiling points of aldehydes and
ketones are higher than
hydrocarbons and ethers of similar
molecular mass.
• Aldehydes and ketones have lower
boiling point than those of alcohols
of similar molecular mass
• The lower members of aldehydes
and ketones are miscible with water
due to the formation of hydrogen
bond with water
From primary alcohols and aldehydes
From alkylbenzenes
From nitriles and amides
From Grignard reagents
From Acyl halides and anhydrides
From Esters
Preparation of Carboxylic acids
Physical Properties
Classi�cation Structure of Carboxyl Group
NaHSO3
HCN
H2N-Z
Alcohols
(Ammonia Derivates)
Alpha-H containing carbonyl compounds give Aldol reaction
• Monocarboxylic acids contain one -COOH group • Dicarboxylic acids contain two -COOH groups
Sources
HCOOH
CH3COOH
C3H7COOH
Acetic acid
Butyric acid
Vinegar(Latin: acetum)
Rancid butter(Latin: butyrum)
Formic acid Red ant(Latin: formica)
Formula SourceCommon Name
Aldehydes without alpha-H undergo Cannizzaro's reactionEster (Given by two equivalents
of an aldehyde) Tishchenko reaction
i) RMgX
ii) H3O+
OH-
OH-
Zn-HgConc. HCl
NH2-NH2OH-/Δ
LIAlH4 or NaBH4
Oxidation Carboxylic Acids
Alcohol
Alkane(Wolf Kishner reduction)
Alkane(Clemmensen reduction)
Al(OR)3
Chemical Properties
C
R
R SO3Na
OH
N-ZC
R
R
C
R
R CN
OH
O
H HOC
R
R
O C
R
R
δ+ δ- δ-δ+ δ+ δ+
δ-
CRO H
O
Carbonyl Compounds
C+
H
-O
O..
..
C
H
-O
O+
..C
H
O
O..
..
RCH2OHalkaline KMnO4
H3O+ RCOOH
CH3(CH2)8COOHCH3(CH2)8CH2OHCrO3.H2SO4
Jones reagent
KMnO4.KOHHeat
Benzoic acid
H3O+
CH3 COOK COOH
KMnO4.KOHHeat
Benzoic acid
H3O+
CH2CH2CH3 COOK COOH
Ethanamide Ethanoic acidH3O+
CH3CONH2 CH3COOH + NH3
Benzamide Benzoic acid
H3O+
+ NH3
CONH2 COOH
Ethanamide
+H -OHorRCN
H2ORCOOH
+H -OHor
R C NH2
O
Ethyl butanoate
Butanoic acid
NaOHH3O+
CH3CH2CH2COOC2H5 CH3CH2CH2COONa
CH3CH2CH2COOH
+ C2H5OH
Ethyl benzonate Benzoic acid
H3O+
+ C2H5OH
COOC2H5 COOH
R-Mg-X + O=C=ODry ether
RCOOHCO-MgX+
O
RH3O+
RCOCl
RCOOH
RCOOHRCOO- H3O+-OH/ H2O
–Cl H2O +
–Cl +
2C6H5COOHH2O(C6H5CO)2O
Benzoic acidBenzoic anhydride
C6H5COOHH2OC6H5COOCOCH3Benzoic acid
CH3COOHEthanoic acidBenzoic ethanoic
anhydride
+
1
2
3
4
5
6
ALDEHYDES, KETONES, AND CARBOXYLIC ACIDS - PART III
• Aliphatic carboxylic acids up to nine carbon
atoms are colourless liquids at room
temperature with unpleasant odours.
• Lower aliphatic carboxylic acids are
miscible in water.
• Carboxylic acids have higher boiling points
than aldehydes, ketones and carboxylic
acids of similar molecular masses.
• Aliphatic carboxylic acids may show
oscillation or alternation e�ect in which the
melting point of an acid with even number
of carbon atoms is more than that of the
next odd homologue.
• The pure or water free form of acetic acid is
also called glacial acetic acid.
Physical Properties• Methanoic acid: Rubber, textile, dyeing,
leather and electroplating industries
• Ethanoic acid: Used as solvent and as
vinegar in food industry
• Hexanedioic acid: Used in the manufacture
of nylon-6, 6
• Esters of benzoic acid: Used in perfumery
• Sodium benzoate: Used as a food
preservative
• Higher fatty acids: Used for the
manufacture of soaps and detergents
Reactions Involving Cleavage of O–H Bond
Reactions Involving Cleavage of C–OH Bond
Reactions Involving –COOH Group
Uses of Carboxylic acid
Chemical Properties
Formation of anhydride
Halogenation
Ring Substitution
Esterification
Reactions with PCl5, PCl3 and SOCl2
Reaction with ammonia
C CRO H
HOR
O
O
H+
RCOOH + R’OH RCOOR’ + H2O
H+
RCOOH + PCl5 RCOCl + POCl3 + HCl
H+
3RCOOH + PCl3 3RCOCl + H3PO3
H+
RCOOH + SOCl2 RCOCl + SO2 + HCl
(i) X2/ phosphorus
α - Halocarboxylic acid
(iI) H2OR-CH2-COOH R-CH - COOH
XX = Cl, Br
2R-COOH + 2Na 2R-COONa+ + H2–
Sodium carboxylate
R-COOH + NaOH R-COONa+ + H2O–
–R-COOH + NaHCO3 R-COONa+ + H2O + CO2
CO
OHH3C C
O
OHH3C
Ethanoic anhydride
CO
OCH3 C
OCH3+
H+, ∆
or P2O5, ∆
m-Nitrobenzoic acid
COOH COOH
NO2Conc. H2SO4
Conc. HNO3
m - Bromobenzoic acid
COOH COOH
BrConc. H2SO4
Br2/ FeBr3
Ammonium acetate AcetamideCH3COOH CH3COONH4
- ++ CH3CONH2+ NH3
-H2O∆
Ammonium benzoate Benzamide
+ NH3
COOH CONH2
-H2O
∆COONH4
- +
Ammonium phthalate
Phthalimide
+ NH3
-NH3Strongheating
COOH
COOH
COONH4- +
COONH4- +
CONH2
CONH2
NH
C
O
O
C
-2H2O
∆
Reactions Involving –COOH Group
Reduction
Decarboxylation
(i) LiAlH4/ ether or B2H6
(iI) H3O+R-COOH RCH2OH
NaOH & CaOHeat
R-COONa R-H + Na2CO3
3
4
1
2
1
2
3
4
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