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Amines and Amides
Amines
H (or R’)
R-N
 functional group: amino
 weakly basic
 often have unpleasant odours
 boiling point and solubility
 higher than comparable hydrocarbons
 lower than comparable alcohols
 N-H bond is less polar than O-H bond
H (or R”)
subclassification: based on the number of alkyl
groups that are attached to the N atom
 primary (1°), secondary (2°), or tertiary (3°)
H
H-N-H
ammonia
H
R-N-H
R’
R-N-H
R’
R-N-R”
1° amine
2° amine
3° amine
Same type of classification as seen in alcohols,
amides, and alkyl substituent groups
Naming Amines
Name as an amino derivative of an alkane (IUPAC)
For a primary amine:
Identify the longest carbon chain that is attached to the
–NH2 group.
2. Add the prefix amino- to the front of the alkane name.
3. Use a number to identify the location of the NH2.
1.
Solution:
• the parent chain has four carbons
• NH2 group attached to C2
2-aminobutane
For a secondary or tertiary amine:
4. use the N-prefix to denote the substituted groups on the
N atom of the amino group.
Solution:
• the parent chain has two
carbons
• the –NH2 group is attached to C1
• two additional CH3 groups
attached to the N
N, N-dimethyl-1-aminoethane
Name this amine. Is it a primary, secondary, or tertiary amine?
CH3 CH2 CH2 – N – CH2 CH3
H CH3
Solution
 parent chain has three carbons
 amino group is attached to C2
 isopropyl group attached to the nitrogen
Secondary amine
N-isopropyl-1-aminopropane
OR
N-propyl-2-aminopropane
Polyamines
 amines that contain more than one –NH2 group
 prefixes: #, #-diamino- (2) and #, #, #-triamino- (3)
 when naming, use numbers to indicate locations of
ALL NH2 groups
NH2 NH2
CH2 C CH3
NH2
1,2,2-triaminopropane
Practice: Naming
A)
C)
B)
Amides
 functional group: amide
R
N
R’ (or H)
R” (or H)
 weakly basic
 boiling point and solubility
 higher than comparable hydrocarbons and all other
compounds
 most polar functional group!
 can accept H bonds and form H bonds (if 1° or 2 ° amide)
Naming Amides
suffix: -amide
For a primary amide (N is attached to one C – the carbonyl):
1. Identify the longest carbon chain that includes the C=O
portion of the amide group.
2. Change the ending to –amide.
3. Identify and name any substituent groups. Numbering
starts at the amide end.
Solution:
• the parent chain has five carbons
• ethyl group attached to C2
2-ethylpentanamide
N,N,3-trimethylbutanamide
For secondary and tertiary amides:
4. Carbon chains attached to the nitrogen: name these first,
as alkyl groups, with N-prefix
Solution
 parent chain has four carbons
 a benzene ring (phenyl group) is attached to the N
N-phenylbutanamide
Practice: Naming
A)
B)
C)
Reaction: Preparation of Amides
 condensation reaction between a carboxylic acid
and an amine
 catalyzed by strong acid (H2SO4)
O
RC-O H
carboxylic acid
+
H
H N-R’
amine
H2SO4
H2O
O
RC-N-R’
H
O
CH3C-OH + HN(H)-CH2CH2CH3
amine
carboxylic acid
H2SO4
O
CH3C-N(H)-CH2CH2CH3
amide
name the reactants
b) name the amide that is produced
c) in the amide name, which part is named first
– the part derived from the acid, or from the amine?
d) what is the other product of this reaction?
a)
O
CH3(CH2)2C-N(H)-(CH2)5CH3
a)
Draw the expanded structural formula for this molecule.
b)
Name the amide.
c)
Draw and name the two reactants that could be used to
prepare this ether.
Homework
 Read 1.8 (Nelson 12)
 Amines– Pg. 69-72
 Amides – Pg. 74-76
 AP unit package: Alcohols, Ethers, and
Amines #10, 11a-d
 AP unit package: Aldehydes, Ketones,
Carboxylic Acids, and Esters #8c,d, 10b