Carboxylic Acid
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Transcript of Carboxylic Acid
Carboxylic Acid
Among important examples are :
COOH
H H H
H
H
HH
OH
OH
HO
Cholic acid(a major component of human bile)
S SCOOHHOOC
NH2 NH2
Was first isolated by Van Veen and Hyman from the urine of the natives of Java who had eaten the djenkol bean and were suffering from poisoning.
Djenkolic acid
Carboxylic Acid
also, biological precursors of fats and other lipids :
CC
CH3(CH2)7 (CH2)7COOH
HH
Oleic acid
CC CC
(CH2)7COOHCH3(CH2)4 CH2
HHHH
Linoleic acid
Carboxylic Acid
This compounds contain the carboxylic group attached to :
O
C
OHH
A hydrogen
and
O
C
OHR
Alkyl group
or
O
C
OHAr
A ryl group
HCOOH
example
CH3COOH
Formic acid
CH3(CH2)10COOH
Acetic acid
Lauric acid
COOH
Benzoic acid
CH2COOH
Penylic acetic acid
Carboxylic Acid
Carboxylic acid that are derivated from open-chain alkanes are systematically named by replacing the terminal –e of the corresponding alkane with –oic acid.
The carboxylic carbon atom is always numbered C1 in the system.
NomenclatureNomenclature
Propanoic acid 4-Methylpentanoic acid 3-Ethyl-6-methyloctanedioic acid
IUPACname
Carboxylic Acid
To indicate the position of attachment, the Greek letters, α, β, γ, δ, etc are used.
NomenclatureNomenclature
COMMONname
The α-carbon is the one bearing the carboxyl group.
C-C-C-C-COOHδ α βγ
CH3CH2CH-COOHα βγ
CH3
α- Methylbutyric acid
CH3CH2CH-CHCOOHα βγ
CH3
α,β -Dimethylvaleric acid
CH3
Carboxylic Acid Physical PropertiesPhysical
Properties
Gugus –C=O pada asam karboksilat mempunyai ikatan π, sehingga dapat terjadi resonansi.
Hal yang sama tidak terjadi pada gugus –OH dari alkohol.
C O C Oσ+ σ- Atom O pada karboksilat lebih
bermuatan negatif daripada R-OH
Atom H pada karboksilat lebih bersifat sebagai proton daripada R-OH
Kesimpulan
Ikatan hidrogen pada karboksilat lebih kuat dari ikatan hidrogen pada alkohol.
Carboxylic Acid Physical PropertiesPhysical
Properties
C
O
OCH3
H
CO
O
H3CH
2 Hydrogen bond
Acetic acid DIMER
O
H
R HO
R1 Hydrogen bond
Still MONOMER
The Fact Boiling point of asetic acid = 118 Co
Boiling point of n-Propylalcahol = 97 Co
Carboxylic Acid DissociationDissociation
Like other Bronsted-Lowry acids, carboxylic acid dissociate slightly in dilute aqueous solution to give H3O+ and carboxylic anion, RCOO-
COH
O
RC
O-
O
R+ H2O +
H3O+
As with all acids, we can define an acidity constant, Ka:
Ka = [RCOO-][H3O+]
[RCOOH]and pKa = -log Ka
pKa = -7 pKa = 4,72 pKa = 16
acidity
Carboxylic Acid ResonanceEfect
ResonanceEfect
CH3CH2OH + H2O + H3O+CH3CH2O-
Unstabilized
Ethanol
CO
O
H3CH
+ H2O CO-
O
H3C CO
O-
H3C + H3O+
Resonance stabilized carboxylic ion
Carboxylic Acid SubstituentEfect
SubstituentEfect
STRUCTURE Ka pKaHCl 107 -7
F3CCOOH 0,59 0,23
Cl3CCOOH 0,23 0,64
HCOOH 1,77 x 10-4 3,75
CH3COOH 1,8 x 10-5 4,72
acidity
Carboxylic Acid PreparationPreparation
1. Oxidation of primary alcohol. R-CH2OH KMnO4 R-COOH
CH3CH2CHCH2OH
CH3
KMnO4
2-Methyl-1-butanol
CH3CH2CHCOOH
CH3
2-Methylbutanoic acid
CH3CHCH2OH
CH3
Isobutyl alcohol
KMnO4 CH3CHCOOH
CH3
Isobutylic acid
R-C N
Carboxylic Acid PreparationPreparation
2. Hydrolysis of Nitriles. R-COOH
or
Ar-C N
+ H2OAcid or base
or
Ar-COOH
+ NH3
CH2CN
Phenylacetonitrile
70% H2SO4
CH2COOH
Phenylacetic acid
3. Carbonation of Grignard Reagents.
4. Oxydation of Alkylbenzenes.
5. Malonic Ester Syntesis.
Derivatives of
Carboxylic Acid
CR
O
OH
CR
O
ClAcid chloride
CR
O
OC
R
O
C
R
Anhydride
O
NH2
Amide
CR
O
OR’Ester
Morereactive
Lessreactive
Derivatives of
Carboxylic AcidNomenclatur
eNomenclatur
e
COH
OH3C C
OH
O
C
Cl
O
Acetic acid Benzoic acid
ArR
Change: -ic acid to –yl chloride
CCl
OH3C
Acetyl chloride Benzoyl chloride
Change: acid to anhydride
CO
OH3C
CO
H3C
Acetic anhydride
C
O
O
C
O
Benzoic anhydride
Acid chloride
Anhydride
Derivatives of
Carboxylic AcidNomenclatur
eNomenclatur
e
COH
OH3C C
OH
O
Acetic acid Benzoic acid
ArR
Change: -ic acid to –amide
Change: acid to -ate
CNH2
OH3C
Acetamide
C
NH2
O
Benzamide
C
OC2H5
O
COC2H5
OH3C
Ethylacetate Ethylbenzoate
Amide
Ester
Derivatives of
Carboxylic Acid1.Acid
Chloride[an Acyl)
1.Acid Chloride[an Acyl)
Carboxylic Acids are converted into acid chlorides [an acyl group] by teratment with thyonyl chloride (SOCl2), phosphorus trichloride
(PCl3), or oxalyl chloride (ClCOCOCl).
CR
O
OH
+ SOCl2 CR
O
Cl
+ SO2+ HCl
Derivatives of
Carboxylic Acid
Conversion to :
OHC
R
O
ORC
R
O
NH2
CR
O
HC
R
O
HCH
R
OH
H2O
ROH NH3
[H]
[H]
EsterAcid Amide Aldehyde
Alcohol
ClC
R
O
RC
R
O
R’’MgX
Ketone
t-alcohol
OR
CR
OH
R
R’’MgX
Derivatives of
Carboxylic Acid
With H2O can converted back into carboxylic acid. C
OH
OH3C
Acetic acid
Acetyl chloride
With alcohol can…………………………..
Benzoyl chloride
C Cl
O
H3C + HClHOH
C ClO HOCH3C OCH3O
Methylbenzoate
Ester
+ HCl
Amide formation with amonia. C Cl
O
H3CAcetyl chloride
+ 2NH3 C NH2
O
H3C + NH4ClAcetamide
Derivatives of
Carboxylic Acid2.Acid Anhydrides2.Acid Anhydrides
Preparation :
CCl
O
CH3
CH
O
O-Na+
+C
O
O
CH3
CH
O
Sodium formate Acetyl chloride Acetic formic anhydride
Derivatives of
Carboxylic Acid
Conversion to :C
O
O
RC
R
O
OHC
R
O
ORC
R
O
NH2
CR
O
HC
R
O
HCH
R
OH
H2O
ROH NH3
[H]
[H]
EsterAcid Amide Aldehyde
Alcohol
Derivatives of
Carboxylic Acid
In drugs industry :
NH2
HO
p-Hydroxyaniline
+
O
H3CC O CCH3
ONaOH
N
HO
H
CO
CH3
Acetaminophen
+ O-H3CC
O
C
O
OH
OH
Salicylic acid
+
O
H3CC O CCH3
ONaOH
C
O
OH
O
CO CH3
Aspirin
+ O-H3CC
O
Derivatives of
Carboxylic Acid
Ester is hydroxy group ini acid change into some alkyl or aryl:
3. Ester3. Ester
The ester linkage is also present in animal fats and many biologically important molecules.
CH3CH2CH2C-OCH3
O
Methylbutanoate[from pineaples]
CH3CO-CH2CH2CHCH3
O CH3
Isopentyl acetate[from bananas] A fat
H2C O
HC O
H2C O
C
C
C
O
O
O
R
R
R
Derivatives of
Carboxylic Acid
Conversion to :
OHC
R
O
NH2
CR
O
HC
R
O
HCH
R
OH
H2O
R’’MgX NH3
[H]
[H]
t-alcoholAcid Amide Aldehyde
Alcohol
ORC
R
O
OR
CR
OH
R
+ H-OR
Derivatives of
Carboxylic Acid
Esters are usually prepared by the reaction of alcohols or phenols with acids or acid derivatives.
C OH
O
R C OR
O
R + H-OH
Carboxylic acid alcohol ESTER
CH2OH + HOOCCH3 CH2OOCCH3 + H-OH
Benzyl alcohol Acetic acid Benzyl acetat
ESTERIFICATION
Derivatives of
Carboxylic AcidSAPONIFICATION
ORC
R
OH2O
NaOH
OHC
R
O+ ROH
O-Na+C
R
O
An acid
A soap
Amine
Amine is derivates of ammonia, when one or more of hydrogen change into alkyl (R) or aryl (Ar).
NH H
H
NR H
H
NR R
H
NR R
R
Ammonia Primary
1o
Secondary
2o
Tertiary
3o
Amine
N
N
CH3
N
N
N
H3C
O
O CH3
CH3
Vitamin B2
N
N
N
N
H
OH3C
H3C
O
H2C CH
CH
CH
CH2OH
OH OH OH
N
NH2C N+
H
H3C
CH2CH2OH
H3C
Nicotine Caffeine
Vitamin B1
Amine Nomenclature
Aliphatic amine are named by naming the alkyl group or groups attached to nitrogen, and following these by the word –amine.
H3C C
CH3
CH3
NH2
H3CH2C N
H
CH3
tert-Butylamine Etrhylmetylamine
Amine Nomenclature
Aromatic amine those in which nitrogen is attached directly to an aromatic ring, are generally named as derivatives of the simple aromatic amine, -aniline.
NH2
aniline
NH2
Br
Br
Br
2,4,6-Tribromoaniline
NH3C C2H5
N-Ethyl-N-methylaniline
NH3C CH3
NO
p-Nitroso-N, N-dimethylaniline
NH2
CH3
p-Touidine
Amine Physical Properties
Amine are highly polar and therefore have higher boiling point than alkanes of equivalent molecular weight have, but lower boiling point than alcohol or carboxylic acids.
N
RR
HN
RR
H
N
RR
HN
RR
H
N
RR
H
CP’s BP (oC) Mr
CH3CH3 -88,6 30
CH3NH2 -6,3 31
CH3OH +65,0 32
Amine Reaction
CH3COOHCl2
CH2COOH
Cl
NH3
CH2COOH
NH2Acetic acid
Chloroacetic acidGLYSINE
[an amino acid]
CR
O
ClAcid chloride
CR
O
OC
R
O
C
R
Anhydride
O
NH2
Amide
CR
O
OR’Ester
HOCCH2CHCH2CH2CHCH2COH
OCH3
54321 6 7 8
CH2CH3O
HCl
CH3CH2OH
R-C N