1. Copyright © 2004 Pearson Education Inc., publishing as Benjamin Cummings. 1 17.1 Amines 17.2 Naming Amines 17.3 Physical Properties of Amines Chapter 17 Amines and Amides

2. Copyright © 2004 Pearson Education Inc., publishing as Benjamin Cummings. 2 Amines are organic compounds in which one or more H in ammonia, NH 3, is replaced with alkyl or aromatic groups. H H H | | | H—N—H CH 3 —N—H CH 3 —N—CH 3 ammonia Amines

3. Copyright © 2004 Pearson Education Inc., publishing as Benjamin Cummings. 3 Classification of Amines Amines are classified as primary, secondary, or tertiary. In a primary (1°) amine, one carbon group is bonded to the nitrogen atom. A secondary (2°) amine has two carbon groups. A tertiary (3°) amine has three carbon groups. H CH 3 CH 3 | | | CH 3 —N—H CH 3 —N—H CH 3 —N—CH 3 1° 2° 3°

4. Copyright © 2004 Pearson Education Inc., publishing as Benjamin Cummings. 4 Models of Amines The three- dimensional models show the shapes of amine molecules with one or more alkyl groups bonded to the nitrogen atom.

5. Copyright © 2004 Pearson Education Inc., publishing as Benjamin Cummings. 5 Simple amines are named as alkylamines. The alkyl groups bonded to the N atom are listed in alphabetical order in front of amine. CH 3 —CH 2 —NH 2 CH 3 —NH—CH 3 Ethylamine Dimethylamine CH 3 | CH 3 —N—CH 2 —CH 3 Ethyldimethylamine Common Names of Amines

6. Copyright © 2004 Pearson Education Inc., publishing as Benjamin Cummings. 6 In the IUPAC system, amines are named as alkanamines. The –e in the alkane name of the longest chain is changed to –amine. The chain is numbered to locate the amine group and substituents. NH 2 | CH 3 —CH 2 —NH 2 CH 3 —CH—CH 3 Ethanamine 2-Propanamine IUPAC Names of Amines

7. Copyright © 2004 Pearson Education Inc., publishing as Benjamin Cummings. 7 Each alkyl groups bonded to the N atom is named as N-alkyl groups in front of the amine name for the longest chain. HN—CH 3 | CH 3 —CH 2 —CH 2 —NH—CH 3 CH 3 —CH—CH 2 —CH 3 N-Methyl-1-propanamine N-Methyl-2-butanamine Naming Secondary and Tertiary Amines

8. Copyright © 2004 Pearson Education Inc., publishing as Benjamin Cummings. 8 Give the common and IUPAC names and classify as primary, secondary, or tertiary: A. CH 3 —CH 2 —CH 2 —NH 2 CH 3 | B. CH 3 —CH 2 —N—CH 3 Learning Check

9. Copyright © 2004 Pearson Education Inc., publishing as Benjamin Cummings. 9 A. CH 3 —CH 2 —CH 2 —NH 2 1-propylamine, 1-propanamine, 1° CH 3 | B.CH 3 —CH 2 —N—CH 3 ethyldimethylamine, N,N-dimethylethanamine, 3° Solution

10. Copyright © 2004 Pearson Education Inc., publishing as Benjamin Cummings. 10 Write a structural formula for A. 2-pentanamine B. N-methyl-1-butanamine Learning Check

11. Copyright © 2004 Pearson Education Inc., publishing as Benjamin Cummings. 11 A. 2-pentanamine NH 2 | CH 3 —CH—CH 2 —CH 2 —CH 3 B. N-methyl-1-butanamine CH 3 —CH 2 —CH 2 —CH 2 —NH—CH 3 Solution

12. Copyright © 2004 Pearson Education Inc., publishing as Benjamin Cummings. 12 Aromatic Amines  The amine of benzene is named aniline.  Aniline 3-Chloroaniline N-Methylaniline

13. Copyright © 2004 Pearson Education Inc., publishing as Benjamin Cummings. 13 Boiling Points of Amines, Alcohols, and Alkanes The boiling points of amines are higher than alkanes, but lower than alcohols of similar mass.

14. Copyright © 2004 Pearson Education Inc., publishing as Benjamin Cummings. 14 Hydrogen Bonding for Amines The polar N-H bond provides hydrogen bonding in 1°and 2° amines, but not 3°. However, the N-H bonds in amines are not as polar as the O-H bonds in alcohols.

15. Copyright © 2004 Pearson Education Inc., publishing as Benjamin Cummings. 15 Solubility in Water Amines with 1-5 carbon atoms are soluble in water. The N atom in amines forms hydrogen bonds with the polar O-H bond in water.

16. Copyright © 2004 Pearson Education Inc., publishing as Benjamin Cummings. 16 Learning Check Consider the following compounds: 1) CH 3 —CH 2 —CH 2 —NH 2 2) CH 3 —CH 2 —NH—CH 3 3) CH 3 —CH 2 —CH 2 —CH 3 A. Which compound has the highest boiling point? B. Which compound is soluble in water?

17. Copyright © 2004 Pearson Education Inc., publishing as Benjamin Cummings. 17 Solution Consider the following compounds: 1) CH 3 —CH 2 —CH 2 —NH 2 2) CH 3 —CH 2 —NH—CH 3 3) CH 3 —CH 2 —CH 2 —CH 3 A. Which compound has the highest boiling point? 1) CH 3 —CH 2 —CH 2 —NH 2 B. Which compound is soluble in water? 1) CH 3 —CH 2 —CH 2 —NH 2 2) CH 3 —CH 2 —NH—CH 3

18. Copyright © 2004 Pearson Education Inc., publishing as Benjamin Cummings. 18 19.4 Amines React as Bases 19.5 Heterocyclic Amines and Alkaloids Chapter 19 Amines and Amides

19. Copyright © 2004 Pearson Education Inc., publishing as Benjamin Cummings. 19 Like ammonia, amines are weak bases in water. NH 3 + H 2 O NH 4 + + OH – ammonium hydroxide CH 3 —NH 2 + H 2 O CH 3 —NH 3 + + OH – methylammonium hydroxide Amines React as Bases

20. Copyright © 2004 Pearson Education Inc., publishing as Benjamin Cummings. 20 An amine salt: Forms when an amine is neutralized by acid. Is named by replacing the amine part of the name with ammonium followed by the name of the negative ion. CH 3 —NH 2 + HCl CH 3 —NH 3 + Cl – Methylamine methylammonium chloride Neutralization forms Amine Salts

21. Copyright © 2004 Pearson Education Inc., publishing as Benjamin Cummings. 21 Properties of Amine Salts Amine salts are: Solids at room temperature. Soluble in water and body fluids. The form used for drugs.

22. Copyright © 2004 Pearson Education Inc., publishing as Benjamin Cummings. 22 Cocaine Cocaine is sold illegally as an amine salt. Cocaine is reacted with NaOH to produce the free amine form known as “crack.”

23. Copyright © 2004 Pearson Education Inc., publishing as Benjamin Cummings. 23 Heterocyclic Amines In a heterocyclic amine, a five- or six-atom ring contains one or more nitrogen atoms.

24. Copyright © 2004 Pearson Education Inc., publishing as Benjamin Cummings. 24 Alkaloids are: Physiologically active nitrogen-containing compounds. Produced by plants. Used as stimulants, anesthetics, and antidepressants. Often habit forming. Alkaloids

25. Copyright © 2004 Pearson Education Inc., publishing as Benjamin Cummings. 25 Caffeine: Is a stimulant of the central nervous system. Is found in coffee beans, tea, chocolate, and soft drinks. Contains an imidazole ring. Caffeine

26. Copyright © 2004 Pearson Education Inc., publishing as Benjamin Cummings. 26 Nicotine Nicotine: Increases the adrenaline level in the blood. Causes addiction to tobacco. Contains a pyrrolidine ring.

27. Copyright © 2004 Pearson Education Inc., publishing as Benjamin Cummings. 27 Alkaloids Related to Morphine Alkaloids such as morphine and codeine are produced by the poppy. For centuries, morphine and codeine have been used as painkillers. Heroin is a modification of morphine.

28. Copyright © 2004 Pearson Education Inc., publishing as Benjamin Cummings. 28 Pharmacology An area of research in pharmacology is to design drugs with some of the characteristics of alkaloids. The structures of cocaine and morphine are modified to produce anesthesia, but without the addictive side effects.

29. Copyright © 2004 Pearson Education Inc., publishing as Benjamin Cummings. 29 Pharmacology Parts of the morphine structure that produce anesthesia are found in procaine, lidocaine, and demerol.

30. Copyright © 2004 Pearson Education Inc., publishing as Benjamin Cummings. 30 Learning Check Identify the heterocyclic amine in serotonin. serotonin

31. Copyright © 2004 Pearson Education Inc., publishing as Benjamin Cummings. 31 Solution Identify the heterocyclic amine in serotonin. pyrrole

32. Copyright © 2004 Pearson Education Inc., publishing as Benjamin Cummings. 32 Chapter 17 Amines and Amides

33. Copyright © 2004 Pearson Education Inc., publishing as Benjamin Cummings. 33 In amides, an amino group replaces the –OH group of carboxylic acids. OO || || CH 3 — C — OH CH 3 — C — NH 2 Amides

34. Copyright © 2004 Pearson Education Inc., publishing as Benjamin Cummings. 34 Preparation of Amides Amides are produced by reacting a carboxylic acid with ammonia or an amine (1° or 2°). O O   CH 3 —C—OH + NH 3 CH 3 —C—NH 2 + H 2 O O O   CH 3 —C—OH + CH 3 —NH 2 CH 3 —C—NH—CH 3 + H 2 O

35. Copyright © 2004 Pearson Education Inc., publishing as Benjamin Cummings. 35 Amides are named as alkanamides. In the IUPAC and common names, the –oic acid or - ic acid endings are replaced by –amide. O  Methanamide (IUPAC) H—C—NH 2 Formamide (common) O  Propanamide (IUPAC) CH 3 —CH 2 —C —NH 2 Propionamide (common) Naming Amides

36. Copyright © 2004 Pearson Education Inc., publishing as Benjamin Cummings. 36 An alkyl group bonded to the N atom is named as N-alkyl in front of the amide name. O  CH 3 —C—NH —CH 3 N-methylethanamide (IUPAC) N-methylacetamide (common) O CH 3   CH 3 —CH 2 —C —N —CH 3 N,N-dimethylpropanamide N,N-dimethylpropionamide Naming Amides with N Groups

37. Copyright © 2004 Pearson Education Inc., publishing as Benjamin Cummings. 37 Aromatic Amides The amide of benzene is named benzamide.

38. Copyright © 2004 Pearson Education Inc., publishing as Benjamin Cummings. 38 Classification of Amides Amides are classified according to the number of carbon atoms bonded to the nitrogen atom. O H || | CH 3 —C—N—H Primary (1°) amide O H || | CH 3 —C—N—CH 3 Secondary (2°) amide O CH 3 || | CH 3 —C—N—CH 3 Tertiary (3°) amide

39. Copyright © 2004 Pearson Education Inc., publishing as Benjamin Cummings. 39 Give the common and IUPAC names for the following amides and classify as primary, secondary, or tertiary: O || A. CH 3 —CH 2 —CH 2 —C—NH 2 O CH 3 || | B. CH 3 —C—N—CH 2 —CH 3 Learning Check

40. Copyright © 2004 Pearson Education Inc., publishing as Benjamin Cummings. 40 O || A. CH 3 —CH 2 —CH 2 —C—NH 2 butryamide (common); butanamide (IUPAC) primary(1°) amide O CH 3 || | CH 3 —C—N—CH 2 —CH 3 N-ethyl-N-methylacetamide (common); N-ethyl-N-methylethanamide (IUPAC) tertiary (3°) amide Solution

41. Copyright © 2004 Pearson Education Inc., publishing as Benjamin Cummings. 41 Draw the condensed structures of A.Pentanamide B. N-methylbenzamide Learning Check

42. Copyright © 2004 Pearson Education Inc., publishing as Benjamin Cummings. 42 A.Pentanamide O || CH 3 —CH 2 —CH 2 —CH 2 —C—NH 2 Solution

43. Copyright © 2004 Pearson Education Inc., publishing as Benjamin Cummings. 43 Amides in Health and Medicine Urea is the end product of protein metabolism. Saccharin is an artificial sweetener. Some amides such as phenobarbital, Nembutal and Seconal are barbiturates. Acetaminophen is used to reduce fever and pain.

44. Copyright © 2004 Pearson Education Inc., publishing as Benjamin Cummings. 44 Amides in Health and Medicine

45. Copyright © 2004 Pearson Education Inc., publishing as Benjamin Cummings. 45 Physical Properties of Amides Hydrogen bonds form in primary and secondary amides, but not tertiary amides. The melting points of primary amides are higher than secondary amides, which have higher melting points than tertiary amides. All amides can form hydrogen bonds with water. Amides with 1–5 carbon atoms are soluble in water.

46. Copyright © 2004 Pearson Education Inc., publishing as Benjamin Cummings. 46 Hydrogen Bonding of Amides O || CH 3 —C—N—H | HHydrogen bonding occurs between primary amides. O || CH 3 —C—N—H | H

47. Copyright © 2004 Pearson Education Inc., publishing as Benjamin Cummings. 47 Amides undergo: Acid hydrolysis to produce a carboxylic acid and ammonium salt. Base hydrolysis to produce the salt of a carboxylic acid and an amine or ammonia. Reactions of Amides

48. Copyright © 2004 Pearson Education Inc., publishing as Benjamin Cummings. 48 acid hydrolysis O || CH 3 —C—OH + NH 4 + Cl - Hydrolysis Reactions O || CH 3 —C—NH 2 O || CH 3 —C—O - Na + + NH 3 HCl + H 2 O NaOH base hydrolysis

49. Copyright © 2004 Pearson Education Inc., publishing as Benjamin Cummings. 49 Write the products of the hydrolysis of N-ethylpropanamide with NaOH. Learning Check

50. Copyright © 2004 Pearson Education Inc., publishing as Benjamin Cummings. 50 Write the products of the hydrolysis of N-ethylpropanamide with NaOH. O || CH 3 —CH 3 —C—O - Na + + CH 3 —CH 2 —NH 2 Solution