This document discusses carboxylic acids. It provides information on analyzing carboxylic acids through litmus tests and reactions with sodium bicarbonate. It also discusses the higher boiling points of carboxylic acids compared to alcohols. Several methods for synthesizing carboxylic acids are described, including oxidation of primary alcohols and aromatic compounds, carbonation of Grignard reagents, and hydrolysis of nitriles. Uses of carboxylic acids include food preservation and medicines. Some negative effects are also mentioned such as skin irritation and air pollution from production.

1. Carboxylic Acid
Analysis, synthesis
and other parts

2. Chemistry for Biologist I
Section-01
Course Instructor: Mohammad Manzur Sharif
Sayeem.
Submitted by
S. M. Jahid Mostofa
ID: 2015-1-77-033

3. 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.

4. Analysis of carboxylic acids
Higher boiling points than similar alcohols,
due to dimer formation.
Acetic acid

5. 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.

6. 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.

7. Carboxylic acids: Synthesis
1. 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.

8. Carboxylic acids: Synthesis
Oxidation 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

9. 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: Synthesis
Oxidation of Aromatic Compounds

10. Grignard Synthesis
Grignard reagent + CO2 yields a carboxylate
salt.
CH3CH3CHCH2MgBr
CH3
CO O CH3CH3CHCH2COO
-
MgBr
+
CH3
H
+
CH3CH3CHCH2COOH
CH3

11. Carbonation of Grignard reagent:
R-X RMgX RCOOMgX RCOOH
Mg CO2 H+
CH3CH2CH2-Br CH3CH2CH2MgBr CH3CH2CH2COOH
n-propyl bromide butyric acid
Mg CO2 H+
C
O
O
RMgX + R C
O
O-
+ +MgX
H+
R C
O
OH
Carboxylic acids: Synthesis

12. CH3
Br
Mg
CH3
MgBr
CO2 H+
CH3
COOH
p-toluic acid
CH3
Br2, hv
CH2Br
Mg
CH2MgBr
CO2
H+
CH2 COOH
phenylacetic acid
Carboxylic acids: Synthesis

13. Carboxylic acids: Synthesis
Hydrolysis of Nitriles
Basic or acidic hydrolysis of a nitrile produces
a carboxylic acid.
Br
NaCN
CN
H
+
H2O
COOH
=>

14. R-X + NaCN  R-CN + H+, H2O, heat  RCOOH
1o alkyl halide
H2O, H+
R-CN R-COOH
heat
H2O, OH-
R-CN R-COO- + H+  R-COOH
heat
Adds one more carbon to the chain.
R-X must be 1o or CH3!
Carboxylic acids: Synthesis

15. Uses for Carboxylic Acids
• Usedto preservefoods becauseit kills bacteriathat
causes foodto spoil
• Usedas pain killersin different parts of Europe
• Used in latex paint
• Used in adhesives

16. CARBOXYLIC ACID
NEGATIVE
EFFECTS

17. Believe It or Not
Okay,it’s really not that
unbelievable but hey...…
give us abreak!

18. Believe It or Not
Did 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).

19. CARBOXLIC ACIDS
…are very important industrially…
… used in the production of polymers,
pharmaceutical solvents and food preservatives

20. CARBOXLIC ACIDS
…its production
causes air pollution

21. CARBOXLIC ACIDS
… can cause skin and
eye irritation

22. CARBOXLIC ACIDS
also causes…
Pulmonary edema and
Breast Cancer

23. CARBOXLIC ACIDS
… is also
persistent organic pollutants

24. Abraham was born with no arms or legs after he was
poisoned by harmful pesticides sprayed on the
fields where his mother was picking tomatoes.

25. No one can deny that
Carboxylic Acids have
indeed done good but
it is up to us to safeguard
and set limits for better.