carboxylic acid analysis, synthesis and other
TRANSCRIPT
Carboxylic Acid
Analys is , synthesis and other parts
Chemistry for Biologist ISection-01
Course Instructor: Mohammad Manzur Sharif Sayeem.
Submitted by
S. M. Jahid Mostofa
ID: 2015-1-77-033
Analysis of carboxylic acids
Litmus test: The blue litmus turn into red.
Sodium bicarbonate test: When add sodium bicarbonate in the solution , a small
bubbles of gas produced.
Analysis of carboxylic acidsHigher boiling points than similar alcohols,
due to dimer formation.
Acetic acid
Analysis of carboxylic acids
• Carboxylic acids are obviously acidic.• Stronger acids than alcohols, but weaker than
mineral acids.• Will react with NaOH to give metal
carboxylates.
Carboxylic acids: Synthesis Oxidation of primary alcohols
Cleavage of an alkenes with hot KMnO4 produces a carboxylic acid if there is a hydrogen on the double-bonded carbon.
Cleavage of an alkynes by ozonolysis.
Oxidation of aromatic compound.
Carbonation of Grignard reagents
Hydrolysis of nitriles.
Carboxylic acids: Synthesis1. oxidation of 1o alcohols:
CH3CH2CH2CH2-OH + CrO3 CH3CH2CH2COOH n-butyl alcohol butyric acid
1-butanol butanoic acid
CH3 CH3
CH3CHCH2-OH + KMnO4 CH3CHCOOH isobutyl alcohol isobutyric acid
2-methyl-1-propanol` 2-methylpropanoic acid
These oxidations are best performed using chromic acid (made from Na2Cr2O7 in H2SO4). Potassium permanganate can be used but gives lower yields.
Carboxylic acids: SynthesisOxidation of Aromatic Compounds
• Benzene does not react with KMnO4.• Alkyl groups on the ring (-R) are readily
oxidized though.• One product for all reactions.
R
+ KMnO4
O
OH
CH3
CH3
H3C
CH2CH3
KMnO4, heat
KMnO4, heat
KMnO4, heat
COOH
COOH
HOOC
COOH
toluene benzoic acid
p-xylene terephthalic acid
ethylbenzene benzoic acid
+ CO2
note: aromatic acids only!
Carboxylic acids: SynthesisOxidation of Aromatic Compounds
Grignard Synthesis
Grignard reagent + CO2 yields a carboxylate salt.
CH3CH3CHCH2MgBr
CH3CO O CH3CH3CHCH2COO
-MgBr
+
CH3H
+
CH3CH3CHCH2COOH
CH3
Carbonation of Grignard reagent:
R-X RMgX RCOOMgX RCOOH
Mg CO2 H+
CH3CH2CH2-Br CH3CH2CH2MgBr CH3CH2CH2COOHn-propyl bromide butyric acid
Mg CO2 H+
C
O
O
RMgX + R CO
O-+ +MgX
H+
R CO
OH
Carboxylic acids: Synthesis
CH3
Br
Mg
CH3
MgBr
CO2 H+
CH3
COOH
p-toluic acid
CH3
Br2, hvCH2Br
MgCH2MgBr
CO2
H+
CH2 COOH
phenylacetic acid
Carboxylic acids: Synthesis
Carboxylic acids: Synthesis Hydrolysis of Nitriles
Basic or acidic hydrolysis of a nitrile produces a carboxylic acid.
BrNaCN
CNH
+
H2O
COOH
=>
R-X + NaCN R-CN + H+, H2O, heat RCOOH1o alkyl halide
H2O, H+
R-CN R-COOH heat
H2O, OH-
R-CN R-COO- + H+ R-COOH heat
Adds one more carbon to the chain.R-X must be 1o or CH3!
Carboxylic acids: Synthesis
Uses for Carboxylic Acids
• Used to preserve foods because it kills bacteria that causes food to spoil
• Used as pain killers in different parts of Europe
• Used in latex paint• Used in adhesives
CARBOXYLIC ACID
NEGATIVE EFFECTS
Believe It or NotOkay, it’s really not that unbelievable
but hey...… give us a break!
Believe It or NotDid you know…
Some forms of Carboxylic Acid are used as an illegal
depressant in some European countries.
Did you know…The burn in your side when you run a lot is
caused by Lactic acid (a Carboxylic Acid).
CARBOXLIC ACIDS…are very important industrially…
… used in the production of polymers, pharmaceutical solvents and food preservatives
CARBOXLIC ACIDS…its production
causes air pollution
CARBOXLIC ACIDS… can cause skin and
eye irritation
CARBOXLIC ACIDSalso causes…
Pulmonary edema and Breast Cancer
CARBOXLIC ACIDS… is also
persistent organic pollutants
Abraham was born with no arms or legs after he waspoisoned by harmful pesticides sprayed on thefields where his mother was picking tomatoes.
No one can deny that
Carboxylic Acids have indeed done good but it is up to us to safeguard
and set limits for better.
Drugs containingCarboxylic acid
EXAMPLES FOR CARBOXYLIC ACIDS INCLUDED IN SOME DRUG :
• 1. Salicylic acid.
• 2.Fusidic acid.
• 3. Citric acid.
• 4. Ascorbic acid.
• 5. Benzoic acid.
• 6.Lactic acid.
• 7.Tartaric acid.
