Amines And Amides
Edith, Aaron and Clark
After this class, you will...
• tell the different types of amines
• recognize the differences between amines
and amides
• know the properties of amines and amides
Amines
• Organic compounds which contain a lone pair
of nitrogen (N)
• Organic bases which react with acids
• Have “fish—like odor”
Methylamine and
3—D model
Review: Functional group
• Groups of atoms or bonds which
determine the special manners of
substances in chemical reactions
Amides
• Compounds with the functional group
RnE(O)xNR'2
• R and R' refer to H or organic groups
Organic amide
sulfonamide
phosphor amide
• most common are "organic amides" (n = 1, E =
C, x = 1)---RCNR
NH2—CO---NH2
Amides
• We can also say,
• compounds with the nitrogen atom which attach
to a carbonyl of R–CO–NR′R″
• Carbonyl: a group which the carbon atom is
double--bonded by the oxygen atom
How to tell amines and amides?
• If we only know the chemical formulas…
• Tell the functional group which
substituents attach to
• Amines---NH2 group
• Amides---CONH2 group
Examples 1
• Amines: CH3-CH2-NH2
• Amides: CH3-CONH2
Practice 1
• CH3-CH2-CH2-CH2-CONH2
• Amide
• H2N-CH2-CH2-CH2-NH2
• Amine
How to tell amines and amides?
•If we only know the names of substances…
•Tell the prefix or suffix of the subtances
•Amines---prefix --- “amino”
---suffix --- “amine”
•Amides---suffix --- “amide”
Examples 2
• 1,4—diaminobutane
• Amine
• Hexanamide
• Amide
Practice 2
• 2—aminopentane
• Amine
• 3,3—dimethylbutanamide
• Amide
Four types of amines
•
Before we begin talking about new
knowledge, we will review a little more…
•
•
Alkyl group
Aromatic ring
• Alkyl group: a hydrocarbon lacking a
hydrogen (CnH2n+1)
Aromatic Ring
• Aromatic means “fragrant”
• It contains benzene
Four types of amines
• Ammonia=NH3
• Primary Amines: one of the three H atoms
is replaced by an alkyl or an aromatic
group (contains at least one C6H6)
• Important: Methylamine--CH3NH2
• Secondary amines:
have two organic
substituents, bound to
N together with one
hydrogen—it means
attaching with single
bond
• If one of the
substituent is double-bond, then there is
no hydrogen bond
Important:
dimethylamine
•
•
Tertiary amines: all three hydrogen
atoms are replaced by organic groups
Important: Triphenylamine---(C6H5)3N
•
•
Cyclic amines: either secondary or
tertiary amines
Important: Aziridines
Naming Amines
• There are several ways to name amines
we'll only talk about the basics.
• The –e in the alkane name of the longest
chain is changed to –amine.
–Example: ethanamine is the amine derived
from ethane
Naming Amines
• We use a number to indicate the location
on the parent (longest) chain:
– Example: 2-propanamine means the nitrogen
is on the second carbon of a propane
Naming Amines
• In secondary and tertiary amines we use
prefix “N” to indicate the substituents
attached to the nitrogen.
– Example: N-Methyl-2-butanamine means a
methyl is attached to the nitrogen
22
Classification of Amides
• The classification of amides is the same
as that of amines.
• Primary amides:1 H is replaced
• Secondary amides:2 H are replaced
• Tertiary amides:3 H are replaced
Naming Amides
• The naming of amides is also similar to
naming amines, except that:
– The suffix for amides is “-amide”
• Example: Propanamide
– The parent chain contains R group and C=O.
• Example: N-propylethanmide
Exercises
• Draw:
–N,N-Dimethyl-1-propanamine
–N,N-Dimethylpropanamide
Chemical properties of Amines
• contain basicity
• easy to form salts if amines react with acids
Uses of Amines
•Primary amines are used to make dyes
•Some amines are beneficial to body, but
some are really harmful,
•Amines are used to make amine drugs
(mimic or interfere neurotransmitters)
Physical Properties of Amides
• Except HCONH2 (Formamide), most
compounds which contain RCONH2 group
are colourless solids
• Liquid amides are great solvents for both
organic and inorganic compounds
Chemical properties of Amides
• Weak bases which compare to amines
• Do not have as clearly noticeable acid—base
properties in water
• Has a greater solubility than other hydrocarbons
in water---the oxygen atom can accept
hydrogen bonds from water and the N-H atoms
can donate H-bonds
Chemical properties of Amides
• it will explode when it meets fire and high
temperature
• it will react with H2SO4, and it will even
explode if the reaction is extremely violent
Use of Amides
• industry: industrial solvents
• medical industry: produce vitamin,
hormone and pesticide