1. Carboxylic Acids and Carboxylic Acid Derivatives
Chapter 14

2. 14.1 Carboxylic Acids Structure and Physical Properties
The carboxyl group of the carboxylic acid consists of a carbonyl group and a hydroxyl group
Both are very polar
This means carboxylic acids are polar
They bond to each other through H-bonding as well as to water molecules
Because of the strong intermolecular bonds of the H-bonds, they boil at higher temps than aldehydes, ketones or alcohols of similar molecular mass

3. 14.1 Carboxylic Acids Structure and Physical Properties
Carbonyl Hydroxyl

4. 14.1 Carboxylic Acids Structure and Physical Properties
Compare boiling points on page 453
Much like alcohols, the smaller the carboxylic acid, the more soluble it is in water.
As the carbon chain grows on the carboxylic acid, solubility decreases because it becomes more like a hydrocarbon and therefore, less polar.

5. 14.1 Carboxylic Acids Structure and Physical Properties
Carboxylic acids with lower molecular masses have a very sour taste and bad smells
Formic acid is what causes the burning when you are bit by an ant!
Acetic acid is found in vinegar
Propionic acid gives swiss cheese its tangy flavor
Butyric acid causes the smell associated with rancid butter and gas gangrene
e/ htm

6. 14.1 Carboxylic Acids Nomenclature (IUPAC)
Determine the parent compound (the longest continuous carbon chain containing the carboxyl group.)
Number the chain so that the carboxyl carbon is carbon-1.
Replace the –e ending of the parent alkane with the suffix –oic acid. If there are 2 carboxyl groups, the suffix –dioic acid is used.
Name and number the substituents the usual way.

7. 14.1 Carboxylic Acids Nomenclature (IUPAC)
A carboxylic acid with 1 carboxyl group
Butanoic Acid
A carboxylic acid with 2 carboxyl groups
Butanedioic Acid

8. 14.1 Carboxylic Acids
Nomenclature (IUPAC)
Name the following:

9. 14.1 Carboxylic Acids Nomenclature (IUPAC)
Carboxylic acid derivatives of cycloalkanes are named by adding the suffix carboxylic acid to the name of the cycloalkane or substituted cycloalkane.
The carboxyl group with always be on carbon-1 and the other substituents named and numbered as usual.

10. 14.1 Carboxylic Acids
Nomenclature (IUPAC)
Name the following:

11. 14.1 Carboxylic Acids Nomenclature (Common)
Table 14.1 on page 456 shows sources of common names
Common names end in –ic rather than –oic.
In this system , substituted carboxylic acids are named as derivatives of the parent compound.
Greek letters are used to indicate position of the substituent. The carbon bonded to the carboxyl carbon is the alpha carbon, the next is beta…and so on.

12. 14.1 Carboxylic Acids Nomenclature (Common) Alpha (α) Beta (β)
Gamma (γ)
Delta (δ)
Epsilon (Ε)
Zeta (ζ)

13. 14.1 Carboxylic Acids Nomenclature (Aromatic Carboxylic acids)
Benzoic acid is the simplest aromatic carboxylic acid
Can be named using either system as derivatives of benzoic acid
The –oic acid or –ic acid is attached to the appropriate prefix
Common names are frequently used (See page 458)

14. 14.1 Carboxylic Acids Nomenclature (Aromatic Carboxylic acids)
The phenyl group is often treated as the substituent and the name comes from the parent chain attached to the benzene (alkanoic parent chain)

15. 14.1 Carboxylic Acids Some Important Carboxylic Acids
Larger carboxylic acids have very strong, foul odors
Pentanoic (valeric) acid from the valerian plant has an aroma described to be like over-ripe cheese or a wet dog
Extracts of it have been used for thousands of years as a sedative
Hexanoic (caproic) acid was first isolated from goats and said to smell like goats.
Heptanoic (enanthic) acid is said to smell like rancid oil.

16. 14.1 Carboxylic Acids Some Important Carboxylic Acids
When carboxylic acids react with alcohols they produce esters which create the fragrance and flavor of many fruits.
More pages

17. 14.1 Carboxylic Acids Reactions Involving Carboxylic Acids
Preparation of carboxylic acids (oxidation reaction)
Carboxylic acids are produced by the oxidation of a primary alcohol or aldehydes.
Chromic acid is a common oxidizing agent.

18. 14.1 Carboxylic Acids Preparation of carboxylic acid
Write the mechanism (equation) for the oxidation of butanol to butanoic acid.

19. 14.1 Carboxylic Acids Acid-Base Reactions
Carboxylic acids behave as acids because they donate protons.
They are weak acids that dissociate to form a carboxylate ion and a hydrogen ion
Carboxylic acids do not completely dissociate (only 5% ions created)

20. 14.1 Carboxylic Acids Acid-Base Reactions
When strong bases are added to carboxylic acid, neutralization occurs.
The hydrogen ions from the acid and hydroxide ions from the base form water.
Carboxylic acid salt is also formed.
+ NaOH → + H2O
Butyric acid Sodium Sodium butyrate Water
hydroxide

21. 14.1 Carboxylic Acids Acid-Base Reactions
Notice that the carboxylic acid salt changed from –ic to –ate.
Acetic acid would become acetate, benzoic acid would become benzoate.
In the front of the name, you place the cation, in this case it was sodium.

22. 14.1 Carboxylic Acids Esterification
Carboxylic acids react with alcohol to form esters and water
R and R1 represent alkyl groups (can be the same or different)
Acid
Carboxylic Alcohol Ester Water

23. 14.2 Esters Structure and Physical Properties
Mildly polar, pleasant aromas
Found in natural foods (banana oil, pineapple, raspberries…etc.)
Boils at approx. same temperature as aldehydes and ketones of similar mass
Somewhat soluble in water

24. 14.2 Esters
Nomenclature
Esters are carboxylic acid derivatives (organic compounds that come from carboxylic acids)
Formed from the reaction of a carboxylic acid and an alcohol
1. Use the alkyl or aryl portion of the alcohol name as the first name
2. The –ic acid ending of the carboxylic acid is replaced with –ate and follows the first name

25. 14.2 Esters
Nomenclature
Examples
Ethyl Butanoate

26. 14.2 Esters Reactions Involving Esters
Preparation of Esters (Esterification)
Dehydration reaction
Requires heat & small amount of acid
Acid
Carboxylic Alcohol Ester Water

27. 14.2 Esters Esterification Example
Write an equation showing the esterification of propyl ethanoate.

28. 14.2 Esters Reactions Involving Esters Hydrolysis of Esters
Hydration reaction (adding water)
Ester Water C.A Alcohol
Requires heat (a small amount of acid may also be added)
Reverse of esterification

29. 14.2 Esters Hydrolysis of Esters Example
Ethyl methanoate Methanoic Ethanol
acid

30. 14.2 Esters Saponification
When you use a base instead of an acid as a catalyst, you make carboxylic acid salt.

31. 14.2 Esters Saponification Examples Propyl ethanoate + water
Propyl hexanoate + water

32. 14.2 Esters Saponification
Fats and oils are triesters of the alcohol, glycerol (they have 3 esters in their structure)
AKA triglycerides- solid fats from animals or liquid oils from plants

33. 14.2 Esters Saponification
Saponification is when esters are hydrated (water added)
Soap is produced (soaps are the salts of long chain carboxylic acids- fatty acid salts)
Roman Legend!- Soap was discovered by washerwomen after a heavy rain on Mons Sapo “Mount Soap.” The rain mixed with the remains of animal sacrifices, wood ash & animal fat. The ingredients of soap accidently came together (H2O, fat & K2CO3/KOH from the ash). The soap ran into the Tiber River where its value was quickly realized.

34. 14.2 Esters Saponification We still make soap the same way
Water, strong base, fats/oils from animals or plants
Solubility of the soap is determined by the C-chain length
Up to 12 carbons is good (has lower mass) and gives larger bubbles
Higher mass carbon chains (14-20 carbons) are less soluble in water and create smaller bubbles and a fine lather
Solubility is also affected by the cation used, whether KOH or NaOH. K+ is more soluble than Na+ when formed with the carboxylic acid.

35. 14.2 Esters Saponification How does soap remove oil/grease?
The long hydrocarbon chain of soaps resembles alkanes & they dissolve other nonpolar compounds (oil/grease- “like dissolves like”).
Large hydrocarbon- hydrophobic
Carboxylate end- hydrophilic
When soap dissolves in water, the carboxylate end dissolves the carbon chain is repelled so a thin layer of soap forms on the surface (chains protrude out).

36. 14.2 Esters Saponification How does soap remove oil/grease?
When soap comes into contact
with oil or grease the C-chain
dissolves in the oil/grease but
the polar carboxylate group
remains dissolved in water

37. 14.2 Esters Saponification How does soap remove oil/grease?
When soap molecules form
around oil/grease, you get micelles. Micelles repel each
other because they are
surrounded by the carboxylate ions in the water.
Mechanical action is what
creates the micelles and
removes them.

38. 14.2 Esters Condensation Polymers Recall from chapter 11
A polymer is a macromolecule made from the combination of smaller monomers
Can be made from a single polymer (same)- “homopolymers.”
OR 2 different monomers- “heteropolymers”

39. 14.2 Esters Condensation Polymers
Polyesters are heteropolymers- also called condensation polymers
Formed by polymerization of monomers in a reaction that forms water or alcohol.
This reaction is created using a dicarboxylic acid and a dialcohol (diol).
DO NOT NEED TO KNOW REACTION

40. 14.2 Esters
Polyesters
When formed as fibers, polyesters are used as fabric for clothing.
Trendy in the 70’s during the disco era, it lost popularity after that.
Along with other synthetic fibers, it has become more popular since the introduction of microfiber technology.

41. 14.2 Esters
Polyester
Can be created into fibers half the diameter of silk. This creates a fabric that drapes, retains its shape, is lightweight, wrinkle resistant & strong.
Polyester is used to make mylar (balloons)
Formed into thin sheets & coated with aluminum foil. Also used as the base for recording tapes and photo film.

42. 14.3 Acid Chlorides and Acid Anhydrides
Carboxylic acid derivative
Nomenclature
Replace the –ic acid ending of the common name with the –yl chloride OR replace the –oic acid ending of the IUPAC name of the carboxylic acid with –oyl chloride.
Butanoyl Chloride

43. 14.3 Acid Chlorides and Acid Anhydrides
Nomenclature Examples

44. 14.3 Acid Chlorides and Acid Anhydrides
Noxious, irritating chemicals
Slightly polar
Boil at approx. the same temperature as aldehydes and ketones of similar mass
React violently with water
Only use is to make esters and amides

45. 14.3 Acid Chlorides and Acid Anhydrides
Synthesis of Acid Chlorides
+ Inorganic products
Carboxylic acid Acid Chloride
The carboxylic acid must react with one of 3 Inorganic acid chlorides seen above and below the reaction arrow.

46. 14.3 Acid Chlorides and Acid Anhydrides
Synthesis of Acid Chlorides
Example
Inorg. Acid chlor.
+ Inorganic products
Benzoic acid Benzoyl Chloride

47. 14.3 Acid Chlorides and Acid Anhydrides
2 carboxcylic acids with a
water removed.
Anhydride means “without
water”
Nomenclature
Symmetrical if both acyl groups are the same.
Name by replacing the acid ending of the carboxylic acid with the word anhydride

48. 14.3 Acid Chlorides and Acid Anhydrides
Nomenclature example
Ethanoic Anhydride

49. 14.3 Acid Chlorides and Acid Anhydrides
Nomenclature
Unsymmetrical anhydrides have 2 different acyl groups
Name by arranging the names of the 2 parent carboxylic acids followed by the word anhydride
Can arrange by size or alphabetical
butanoic pentanoic
anhydride

50. 14.3 Acid Chlorides and Acid Anhydrides
Synthesis of Acid Anhydrides
Cannot form in a reaction with a carboxylic acid.
See pg 479 for mechanism
Acid chloride reacts with a carboxylate ion to form an acid anhydride and a chlorine ion.
Carbox. ion
+ Cl-
Ethanoyl chloride Ethanoic anhydride