1. Carboxylic acids and their derivatives

2. Structure

3. Structure of derivatives
acyl halide
anhydride
acid halide
ester
amide

4. The acyl group

5. Nomenclature HCO2H formic acid (from Latin formica, ant)
CH3CO2H acetic acid (from Latin acetum, vinegar)
CH3CH2CO2H propionic acid (from Greek protos, first and piôn, fat)
CH3(CH2)2CO2H butyric acid (from Latin butyrum, butter)
CH3(CH2)3CO2H valeric acid (valerian root)
CH3(CH2)4CO2H caproic acid (from Latin caper, goat)
CH3(CH2)6CO2H caprylic acid
CH3(CH2)8CO2H capric acid

6. Nomenclature
-aminobutyric acid

7. Nomenclature
-hydroxypropionic acid or lactic acid
isocaproic acid

8. Aromatic acids
p-bromobenzoic acid
m-toluic acid

9. Aldehydes - non-systematic names
form(ic acid)aldehyde
b-methylvaleraldehyde

10. IUPAC CH3CH2CO2H propanoic acid (CH3)2CHCH2CH2CO2H
4-methylpentanoic acid
2-hydroxy-5-methyl-3-hexenoic acid
(CH3)2CHCH=CHCH(OH)CO2H
C-1

11. Cyclic acids
Saturated cyclic acids are named as cycloalkanecarboxylic acids:
cis-2-methylcyclohexanecarboxylic acid

12. Salts of carboxylic acids
sodium benzoate
(CH3CO2)2Ca calcium acetate or calcium ethanoate

13. Nomenclature of derivatives

14. Nomenclature of acyl halides
Change -ic acid to -yl halide

15. Nomenclature of anhydrides
change acid to anhydride

16. Nomenclature of amides
change -ic or -oic acid to -amide

17. Nomenclature of esters
change -ic acid to name of alcohol group or phenol + -ate

18. Order of precedence of functional groups

19. Physical properties Intermolecular hydrogen bonding is very important.
In the solid and liquid states, carboxylic acids exist as dimers. Mp and bp values are far higher than the corresponding alcohols.

20. Physical properties of acid derivatives
Polar compounds: the acyl halides, anhydrides, and esters
have boiling points which are very similar to those of
aldehydes and ketones of equivalent molecular weight.
However, the amides

21. Dissociation of carboxylic acids
~ 10-5

22. Relative acidities
Relative basicities

23. Acidity of carboxylic acids

24. Structure of carboxylate ions

25. Substituent effects CH3CO2H ClCH2CO2H Cl2CHCO2H Cl3CCO2H
Ka x x x x10-5
HCO2H CH3CO2H CH3CH2CH2CO2H
Ka x x x10-5

26. Salts of carboxylic acids
crystalline, non-volatile, decompose on heating to C.
sodium, potassium and ammonium salts are all water soluble and insoluble in non-polar solvents.

27. Salts of carboxylic acids
water insoluble
water soluble
NB: Phenols do not react with bicarbonate.

28. Preparation of carboxylic acids

29. Oxidation of primary alcohols

30. Oxidation of arenes

31. Oxidation of arenes

32. The haloform reaction

33. Carboxylation of Grignard reagents

34. Carboxylation of Grignard reagents
2,2-dimethylpropanoic acid

35. Hydrolysis of nitriles
+ NH3

36. Preparation of nitriles - an SN2 reaction
CH3CH2CH2CH2Br + CN-  CH3CH2CH2CH2CN
primary halide
(CH3)3CBr + CN-  (CH3)2C=CH2 + HCN

37. Nomenclature of nitriles
CH3CH2CN - 3 carbon chain
propane + nitrile = propanenitrile
propionic acid - ic acid + onitrile = propiononitrile
ethanenitrile
acetonitrile
CH3CN
pentanenitrile valeronitrile
CH3(CH2)3CN

38. The acyl group

39. Reactivity of aldehydes and ketones

40. Reactivity of carboxylic acid derivatives – nucleophilic addition - elimination
G = -OH, -X, -OOCR, -NH2, or -OR
Why?

41. Reactivity of carboxylic acid derivatives
The ease of loss of the leaving group, G, depends on its
basicity:
G = HO-, X-, RCO2-, NH2- , or RO-
G = H-, R- ?

42. Reactivity of carboxylic acid derivatives

43. Base hydrolysis

44. Acid hydrolysis

45. SN2 v acyl substitution

46. Nucleophilic displacement - reactivity

47. Haloform reaction

48. Haloform reaction

49. acid chlorides
Use thionyl chloride (SOCl2), phosphorus trichloride (PCl3) or phosphorus pentachloride (PCl5).

50. acid chlorides

51. Reactions of acyl halides - conversion into acids
+ HCl
benzoyl
chloride
benzoic acid

52. Reactions of acyl halides - conversion into amides
+ NH4Cl

53. Reactions of acyl halides - conversion into esters

54. Reactions of acyl halides - Friedel - Crafts’ acylation

55. Reactions of acyl halides with diorganocopper reagents
A Gilman reagent

56. Reactions of acyl halides - the Rosemund reduction
RCHO or ArCHO
A special catalyst is used: palladium on barium sulfate which has been deactivated (poisoned) with an amine such as quinoline.

57. Lithium tri-tert-butoxyaluminium hydride

58. Anhydrides - preparation of acetic anhydride

59. Preparation of other anhydrides
Nucleophilic substitution of an acyl halide with a carboxylate anion.

60. Hydrolysis of anhydrides
acetic acid

61. Aminolysis of anhydrides
+ CH3CO2- NH4+
acetamide
ammonium
acetate

62. Alcoholysis of anhydrides
+ CH3CO2H
methyl
acetate

63. Acylation

64. Preparation of esters

65. Preparation of esters

66. Preparation of esters

67. Reactions - base hydrolysis
rate = k[OH-][ester]
How can we prove that OH- attacks the acyl carbon and not the alkyl carbon?

68. Reactions - base hydrolysis

69. Predicted result for alkyl - oxygen bond breaking

70. Predicted result for acyl - oxygen bond breaking
So what happens when we perform the reaction?
(+)-2-butanol is obtained - [] = +13.8o
acyl - oxygen bond breaking occurs

71. Acyl - oxygen bond breaking - further proof using isotopic labels

72. However......?

74. Reactions - acid hydrolysis+ H OH + R
OR' R O R'

75. Reactions - acid hydrolysis

76. Aminolysis of esters

77. Transesterification

78. Transesterification - acid catalysed

79. Transesterification - basic conditions

80. Transesterification - a preparation of polyvinyl alcohol

81. Reactions of ester with Grignard reagents

82. Preparation of amides

83. Preparation of amides from acyl chlorides

84. Preparation of amides from acyl chlorides
N-phenylbutanamide

85. Reactions - acid catalysed hydrolysis

86. Reactions - base hydrolysis

87. Hofmann degradation

88. Hofmann degradation

89. Reduction of acids
1o alcohol

90. Reduction of esters

91. Hell-Volhard-Zelinsky reaction

92. a-Halocarboxylic acids

93. a-Halocarboxylic acids
dicarboxylic acid

94. Hell-Volhard-Zelinsky reaction
enol

95. Spectroscopy
IR:
C=O stretching ~ 1710 cm-1 (dimer), ~1760 cm-1 (monomer)
O-H stretching - broad range ( cm-1)
NMR:
OH proton occurs in the region  = 9-13 ppm.

96. Problems
Try problems (a - g and m), , 18.21, 18.23, 18.24, 18.28, 18.29, 18.33, 18.35, 18.36, 18.41, and