The document discusses the nomenclature, properties, preparation, and reactions of carboxylic acids and their derivatives. It provides detailed information on naming conventions and reaction mechanisms for carboxylic acids, acid chlorides, anhydrides, esters and other derivatives according to IUPAC rules. Factors that influence the acidity of carboxylic acids are also examined, including resonance, inductive effects, and various substituents. Common preparation methods include oxidation reactions, hydrolysis, and carbonation of Grignard reagents.

1. Part 2
Carboxylic acid and its
derivatives
Nomenclature, Properties,
Preparation and Reactions

2. Carboxylic acid and its
derivatives
2
Carboxylic acids have a carbonyl group bonded to a hydroxyl group, and they have
the general formula

3. Carboxylic acid and its
derivatives
3
acyl compounds
or
carboxylic acid derivatives
Carboxylic acids have a carbonyl group bonded to a hydroxyl group, and they have
the general formula

4. Carboxylic acid
Carboxylic acid
named after alkane by changing the -e of the corresponding
parent alkane to -oic acid. The carboxyl carbon is assigned
position 1.
4
: Nomenclature
IUPAC

5. Carboxylic acid
Carboxylic acid
The common names for many carboxylic acids remain in use: Methanoic
and ethanoic acid are usually referred to as formic and acetic acid
5
: Nomenclature
IUPAC
The functional group of a carboxylic acid is called a carboxylic group:

6. Carboxylic acid
Carboxylic acid
6
: Nomenclature
IUPAC
Carboxylic acids in which a carboxyl group is attached to a ring are named by
adding Carboxylic acid to the name of the cyclic compound

7. Carboxylic acid
Carboxylic acid
7
: Nomenclature
IUPAC
Dicarboxylic acids are named as alkanedioic acids in the IUPAC system
- Common names are often used for simple dicarboxylic acids

8. Ester
Ester
8
: Nomenclature
IUPAC
In naming an ester, the name of R’ group attached to the carboxyl oxygen is
stated first, followed by the name of the acid, with the (ic) acid replaced by
(ate).

9. Ester
Ester
9
: Nomenclature
IUPAC
In naming an ester, the name of R’ group attached to the carboxyl oxygen is
stated first, followed by the name of the acid, with the (ic) acid replaced by
(ate).

10. Salts of Carboxylic Acids
Salts of Carboxylic Acids
10
: Nomenclature
IUPAC
The cation is named first followed by the name of the acid, with (ic) acid
replaced by (ate).

11. Acid Anhydrides
Acid Anhydrides
11
: Nomenclature
IUPAC
Loss of water from two molecules of a carboxylic acid results in an acid
anhydride.
**If the two carboxylic acid molecule forming the acid anhydride are the
same, the anhydride is a symmetric anhydride.
**If the two carboxylic molecules are different, the anhydride is a mixed
anhydride.

12. Acid Anhydrides
Acid Anhydrides
12
: Nomenclature
IUPAC
** Symmetrical anhydrides are named by using the acid name and replacing
acid with anhydride.
**Mixed anhydrides are named by stating the names of both acids in
alphabetical order followed by anhydride.

13. Acid Anhydrides
Acid Anhydrides
13
: Nomenclature
IUPAC

14. Acid Chlorides (acyl halides)
Acid Chlorides (acyl halides)
14
: Nomenclature
IUPAC
Acid chlorides are named by dropping the -ic acid from the name of the
carboxylic acid and adding -yl chloride.
** For acids ending with carboxylic acid, carboxylic acid is replaced with
carbonyl chloride (or bromide).

15. Carboxylic acid derivatives
15
: Nomenclature
IUPAC

16. Carboxylic acid derivatives
16
: properties
• Carbonyl compounds have the following relative boiling points:
➢ amide > carboxylic acid >> ester ~ acyl chloride ~ ketone ~ aldehyde
➢ The boiling points of an ester, acyl chloride, ketone, and aldehyde of
comparable molecular weight are similar and are lower than the boiling point
of an alcohol of similar molecular weight because only the alcohol molecules
can form hydrogen bonds with each other.

17. Carboxylic acid derivatives
17
: properties
• Carbonyl compounds have the following relative boiling points:
➢ amide > carboxylic acid >> ester ~ acyl chloride ~ ketone ~ aldehyde
➢ The boiling points of an ester, acyl chloride, ketone, and aldehyde of
comparable molecular weight are similar and are lower than the boiling point
of an alcohol of similar molecular weight because only the alcohol molecules
can form hydrogen bonds with each other.

18. Carboxylic acid derivatives
18
: properties
• Carbonyl compounds have the following relative boiling points:
✓ Carboxylic acids have relatively high boiling points because each
molecule has two groups that can form hydrogen bonds.
✓ Amides have the highest boiling points because they have strong
dipole–dipole interactions. In addition, if the nitrogen of an amide is
bonded to a hydrogen, hydrogen bonds can form between the molecules

19. Carboxylic acid derivatives
19
: properties
• Carbonyl compounds have the following relative boiling points:
✓ Boiling points of a nitrile is similar of an alcohol because a nitrile
has strong dipoe-dipole interaction

20. Carboxylic acid derivatives
20
: properties
• Acidity of Carboxylic Acids
• The carboxyl proton of most carboxylic acids has pKa = 3 - 5
– Carboxylic acids are readily deprotonated by sodium hydroxide or sodium
bicarbonate to form carboxylate salts
– Carboxylate salts are more water soluble than the corresponding carboxylic acid

21. Carboxylic acid derivatives
21
: properties
• Acidity of Carboxylic Acids
In determining the position of equilibrium for an acid-base reaction, equilibrium
favors reaction of strong acid & strong base & formation of weak acid & weak
base.

22. Carboxylic acid derivatives
22
: properties
• Factors affecting acidity of carboxylic acids
1) Resonance effect
Carboxylic acids are much more acidic than alcohols (both have OH).
Alcohols dissociate to give alkoxide ion, in which the -ve charge is localized on a
single electronegative atom

23. Carboxylic acid derivatives
23
: properties
• Factors affecting acidity of carboxylic acids
1) Resonance effect
Carboxylic acids are much more acidic than alcohols (both have OH).
Alcohols dissociate to give alkoxide ion, in which the -ve charge is localized on a
single electronegative atom

24. Carboxylic acid derivatives
24
: properties
• Factors affecting acidity of carboxylic acids
1) Resonance effect
A carboxylic acid gives carboxylate ion, in which -ve charge is delocalized over
two oxygen atoms. A carboxylate ion is stabilized by resonance.

25. Carboxylic acid derivatives
25
: properties
• Factors affecting acidity of carboxylic acids
1) Resonance effect
A carboxylate ion is a stabilized resonance hybride of two equivalent Kekule
structure & is more stable than alkoxide ion, it is lower in energy & more highly
favored in equilibrium.

26. Carboxylic acid derivatives
26
: properties
• Factors affecting acidity of carboxylic acids
2) inductive effect
Pulling electrons through sigma bonds by a more electronegative atom
electron withdrawing groups (as halogens) increase acidity of carboxylic acids by
inductive effect

27. Carboxylic acid derivatives
27
: properties
• Factors affecting acidity of carboxylic acids
2) inductive effect
Acidity decreases with increasing distance between the electron withdrawing
substituent and the oxygen atom.

28. Carboxylic acid derivatives
28
: properties
• Factors affecting acidity of carboxylic acids
3) substituent effects
Any factor that stabilizes the carboxylate anion relative to undissociated
carboxylic acid will derive the equilibrium toward increased dissociation and
result in increased acidity.
Electron withdrawing groups Electron donating groups
• X, NO2, SO3, CN
• will delocalize the –ve
charge, stabilize the ion
• Increase acidity
• CH3, R, OCH3, NH2, OH
• will destabilize the carboxylate
ion relative to undissociated acid
• Decrease acidity

29. Carboxylic acid derivatives
29
: properties
• Factors affecting acidity of carboxylic acids

30. Carboxylic acid derivatives
30
: properties
• Factors affecting acidity of carboxylic acids

31. Carboxylic acid derivatives
31
: properties
• Factors affecting acidity of carboxylic acids

32. Carboxylic acid derivatives
32
: properties
• Factors affecting acidity of carboxylic acids

33. Carboxylic acid
33
: Preparation
1) Oxidation of Alkenes

34. Carboxylic acid
34
: Preparation
2) Oxidation of Aldehydes & Primary Alcohols

35. Carboxylic acid
35
: Preparation
3) Oxidation of Alkylbenzenes
4) Oxidation of Methyl Ketones (The Haloform Reaction)

36. Carboxylic acid
36
: Preparation
5) Hydrolysis of Cyanohydrins & Other Nitriles:
a) Hydrolysis of a cyanohydrin yields a-hydroxy acid

37. Carboxylic acid
37
: Preparation
5) Hydrolysis of Cyanohydrins & Other Nitriles:
b) Primary alkyl halides can react with cyanide to form nitriles which
hydrolyzed to carboxylic acids

38. Carboxylic acid
38
: Preparation
6) Carbonation of Grignard Reagents
This method is not applicable when groups incompatible with Grignard reaction are present in
the ring, e.g., NH2, NO2, COOH, OH, and SO3H.

39. Decarboxylation of Carboxylic Acids
39
Loss of CO2 from a carboxyl group = Decarboxylation
• Carboxylic acids undergo thermal decarboxylation, when heated to a very high
temperature and most carboxylic acids are resistant to moderate heat.
• Exceptions are carboxylic acids that have a carbonyl group β to the carboxyl group
(β-ketoacids undergo decarboxylation readily on mild heating).

40. General mechanism for
nucleophilic acyl substitution
40
: Reactions
aldehydes & ketones undergo nucleophilic addition to the carbon-oxygen
double bond carbonyl group of carboxylic acids & their derivatives undergo
nucleophilic substitution
a) Negatively charged nucleophile

41. General mechanism for
nucleophilic acyl substitution
41
: Reactions
Nucleophile reacts at the carbonyl group to form a tetrahedral intermediate
The tetrahedral intermediate eliminates a leaving group & The carbonyl group
is regenerated; the net effect is an acyl substitution
aldehydes & ketones undergo nucleophilic addition to the carbon-oxygen
double bond carbonyl group of carboxylic acids & their derivatives undergo
nucleophilic substitution
a) Negatively charged nucleophile

42. General mechanism for
nucleophilic acyl substitution
42
: Reactions
b) Neutral nucleophile

43. General mechanism for
nucleophilic acyl substitution
43
: Reactions
➢Acid chlorides react with loss of chloride ion
➢Anhydrides react with loss of a carboxylate ion

44. General mechanism for
nucleophilic acyl substitution
44
: Reactions
➢Acid chlorides react with loss of
chloride ion
➢Anhydrides react with loss of a
carboxylate ion
➢Esters, carboxylic acids and amides
generally react with loss of the leaving
groups alcohol, water and amine,
respectively.
➢Aldehydes and ketones cannot react
by this mechanism because they lack
a good leaving group

45. General mechanism for
nucleophilic acyl substitution
45
: Reactions
Relative Reactivity of Acyl Compounds
-In general, reactivity can be related to the ability of the leaving group to
depart. Leaving group ability is inversely related to basicity
- Chloride is the weakest base & the best leaving group
- Amines are the strongest bases & the worst leaving groups

46. General mechanism for
nucleophilic acyl substitution
46
: Reactions
Relative Reactivity of Acyl Compounds
As a general rule, less reactive acyl compounds can be synthesized from
more reactive ones.
Synthesis of more reactive acyl derivatives from less reactive ones is difficult
and requires special reagents (if at all possible)

47. Acid Chlorides
47
: Synthesis
From carboxylic acids
from reaction of carboxylic acids with SOCl2, PCl3, PCl5. These reagents turn
the OH group of the carboxylic acid into an excellent leaving group

48. Acid Chlorides
48
: Synthesis
From carboxylic acids
from reaction of carboxylic acids with SOCl2, PCl3, PCl5. These reagents turn
the OH group of the carboxylic acid into an excellent leaving group

49. Acid Chlorides
49
: Reactions
Acyl chlorides are the most reactive acyl compounds & can be used to make
any of the other derivatives
Since acyl chlorides are easily made from carboxylic acids they provide a
way to synthesize any acyl compound from a carboxylic acid.
Acid chlorides react with carboxylate ion to form anhydride.

50. Acid Chlorides
50
: Reactions
Acyl chlorides are the most reactive acyl compounds & can be used to make
any of the other derivatives
Acid chlorides react with carboxylate ion to form anhydride.

51. Acid Chlorides
51
: Reactions
Acid chlorides react with alcohol to form esters
Acid chlorides react with water to form acid

52. Acid Chlorides
52
: Reactions
Acid chlorides react with amines to form amides
Reaction of acyl chlorides with ammonia, 1ry or 2ry amines must be carried
out with excess amine so that there will be enough amine to react with acyl
chloride

53. Acid Chlorides
53
: Reactions
Acid chlorides react with amines to form amides
Reaction of acyl chlorides with ammonia, 1ry or 2ry amines must be carried
out with excess amine so that there will be enough amine to react with acyl
chloride

54. Acid Chlorides
54
: Reactions
Acid chlorides react with amines to form amides
Reaction of acyl chlorides with ammonia, 1ry or 2ry amines must be carried
out with excess amine so that there will be enough amine to react with acyl
chloride
Because tertiary amines cannot form amides, an equivalent of tertiary amine
such as triethylamine or pyridine can be used instead of excess amine.

55. 3. Carboxylic Acid Anhydrides
55
: Preparation
From Acid chlorides
Acid chlorides react with carboxylic acids to form mixed or symmetrical
anhydrides
It is necessary to use a base such as pyridine
Sodium carboxylates react readily with acid chlorides to form anhydrides

56. 3. Carboxylic Acid Anhydrides
56
: Preparation
From cyclic anhydrides with 5- & 6-membered rings
It can be synthesized by heating appropriate diacid

57. 3. Carboxylic Acid Anhydrides
57
: Reactions
Hydrolysis of an anhydride
It yields the corresponding carboxylic acids

58. 3. Carboxylic Acid Anhydrides
58
: Reactions
Synthesize esters & amides
Carboxylic acid anhydrides are very reactive & can be used to
synthesize esters & amides
**In the reaction with
amine, 2 mol of amines or
1 mol of amine + 1 mol of
3ry amine such as
pyridine must be used to
react with the carboxylate
ion produced in the
reaction.

59. 4. Esters
59
: Preparation
From carboxylic acid :Esterification
1) Acid catalyzed reaction of alcohols & carboxylic acids to form esters is
called Fischer esterification

60. 4. Esters
60
: Preparation
From carboxylic acid :Esterification
Fischer esterification is an
equilibrium process:
• Ester formation is favored
by use of a large excess of
either the alcohol or
carboxylic acid.
• Ester formation is also
favored by removal of water

61. 4. Esters
61
: Preparation
From Acid Chlorides
Acid chlorides react readily with alcohols in the presence of a base (e.g. pyridine) to
form esters

62. 4. Esters
62
: Preparation
From Acid Anhydrides
Alcohols react readily with anhydrides to form esters

63. 4. Esters
63
: Reactions
1) Hydrolysis:
Esters react with water (acid or base) to form carboxylic acid & alcohol.
a) Acid Hydrolysis

64. 4. Esters
64
: Reactions
1) Hydrolysis:
Esters react with water
(acid or base) to form
carboxylic acid &
alcohol.
a) Acid Hydrolysis

65. 4. Esters
65
: Reactions
1) Hydrolysis:
Esters react with water (acid or base) to form carboxylic acid & alcohol.
b) Base-Promoted Hydrolysis of Esters: (Saponification)
Reaction of an ester with sodium hydroxide results in the formation
of a sodium carboxylate & an alcohol.

66. 4. Esters
66
: Reactions
1) Hydrolysis:
Esters react with water (acid or base) to form carboxylic acid & alcohol.
b) Base-Promoted Hydrolysis of Esters: (Saponification)
The mechanism is reversible until the alcohol product is formed.
- Protonation of the alkoxide by the initially formed carboxylic acid is irreversible
- This step draws the overall equilibrium toward completion of the hydrolysis.

67. 4. Esters
67
: Reactions
1)Hydrolysis:
Esters react with water (acid or base) to form carboxylic acid &
alcohol.
b) Base-Promoted Hydrolysis of Esters: (Saponification)
Soaps are Na or K salts of fatty acids. Soaps are obtained when fats or oils are
hydrolyzed under basic conditions

68. 4. Esters
68
: Reactions
2) Alcoholysis
An ester reacts with alcohol to form a new ester & a new
alcohol

69. 4. Esters
69
: Reactions
3) Aminolysis
An ester reacts with an amine to form amide

70. 4. Esters
70
: Lactones
γ or δ-Hydroxyacids undergo acid catalyzed reaction to give
cyclic esters known as γ or δ lactones, respectively:

71. 4. Esters
71
: Lactones
Lactones can be hydrolyzed with aqueous base. Acidification of
the carboxylate product can lead back to the original lactone if
too much acid is added.