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Functional Groups
Functional groups are
• a characteristic feature of organic molecules
that behave in a predictable, similar way.
• composed of an atom or group of atoms.
• groups that replace a hydrogen atom in the
corresponding alkane.
• a way to classify families of organic
compounds.
1
Hydrocarbons
Drugs
Fire accelerants
Petrol:
It is petroleum-derived, and
consists mostly of aliphatic
hydrocarbons enhanced with
iso-octane or the aromatic
hydrocarbons toluene and
benzene to increase its octane
rating.
Diesel:
Diesel is produced from oil and
is a hydrocarbon mixture,
obtained in the fractional
distillation of crude oil between
200 °C and 350 °C at
atmospheric pressure
Butane Gas:
consumed
from lighters
CH3
H3C
C4H10
Carbon tetrachloride:
Used for solvent abuse
CCl4
Cl
Cl
Cl
Cl
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Aromatic compounds
Fire accelerants
HN
N
Benzene
Toluene
Explosives
N
O
Benzodiazepines:
Psychoactive drugs with
varying hypnotic, sedative,
anxiolytic, anticonvulsant,
muscle relaxant and
amnesic properties
CH3
O
Drugs
-
CH3
+
Dyes
O
N
O
O
+
O
O
-
N
OH
-
+
OH
O
O
Tri-Nitro Toluene (TNT)
Alizarin
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cyclic molecules
H
H
H
H
C
H
H
CH2 CH2
H
H
C
C
H
CH2 CH2
H
C
C
H
CH2 CH2
H
Cyclobutane
H
H
C
C
H
H
HH
C
H
H
H
H
C
C
C
C
C
H
CH2
Cyclopentane
C
H
CH2
CH2 CH2
H
H
H
H
CH2
C
C
Cyclopropane
H
H
H
CH2
C
C
H
H
H
CH2
H
H
CH2
CH2
CH2
CH2
CH2
Cyclohexane
Nomenclature for Cyclic Alkanes
• For compounds with a single ring, add the
prefix “cyclo-” to the root name for the
alkane comprising the ring.
Ethers
Fire accelerants
Drugs
Codeine: Opiate alkaloid
H3C
O
HO
CH3
N
CH3
O
Ethyl Ether - diethyl
ether: flash point -45
degrees C; ignition
temperature 180 degrees
C; explosive limits 1.9% 36%
HO
Dyes
H
H
+
N
Cl
-
Rhodamine 123
O
NH2
O
O
CH3
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Ethers
In an ether, an oxygen
atom is bonded to two
carbon atoms.
–C–O–C– .
has a common name
that gives the alkyl
names of the attached
groups followed by
ether.
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Diethyl ether
7
Ethers are named in two ways: the
common naming system, and the IUPAC
naming system
•IUPAC Names: The carbon(s) attached to the
oxygen atom are named as branches by adding
the –oxy suffix to the stem name.
Ether Example
CH3-CH2-CH2-CH2-O-CH2-CH3
• IUPAC Name: ethoxybutane
Ether Practice
R-O_R
• Draw the condensed structural formula of
methoxy propane:
Ketones
Fire accelerants
O
H 3C
CH3
Acetone:(Dimethyl
ketone)
flash point -20 degrees
C; ignition temperature
465.4 degrees C;
explosive limits 2.6%13.0%
Explosives
Drugs
H3C
O
Methcathinone:
2-(methylamino)propiophenone.
Psychoactive
stimulant. Addictive.
Can be smoked,
injected, or taken
orally .
Dyes
O
ACETONE: precursor of TATP.
TATP: The synthesis of the explosive is
made through oxidation of acetone using
hydrogen peroxide
CH3
NH
9,10-dioxoanthracene
O
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4. Ketones
In a ketone, the carbon of
the carbonyl group is
attached to two other
carbon atoms.
Acetone
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12
IUPAC Names for Ketones
• Replace -e with -one. Indicate the
position of the carbonyl with a number.
• Number the chain so that carbonyl
carbon has the lowest number.
• For cyclic ketones the carbonyl carbon
is assigned the number 1.
Chapter 18
13
Ketones Practice
R-C-R
• Draw the condensed structural formula for
3-pentanone
O
CH3
Examples
C CH CH3
CH3
3-methyl-2-butanone
Chapter 18
15
Esters
Fire accelerants
Biodiesel refers to a nonpetroleum-based diesel fuel
consisting of short chain alkyl
(methyl or ethyl) esters
Drugs
O
O
CH3
H2N
Explosives
CH3
O
H3C
O
O
O
Dibutylphatalate:
Plasticizer used in explosives. Plasticizers
are additives that increase the plasticity or
fluidity.
Benzocaine (local anaesthetic) :
Benzocaine is often favoured by drug
dealers to bulk out their cocaine supplies.
while many dealers use the cheaper
paracetamol or corn flour, Benzocaine gives
a numbing effect (like purer cocaine
should have).
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Esters
• Ester – a compound that
has the following general
formula:
14 | 17
Section 14.4
Names of esters
end in –oate.
Naming
Named after alcohol & carboxylic acid from
which they are derived.
O
C
CH3
CH2
CH3
let’s name
some esters!
O
ethyl
this part comes from the
alcohol & is named after it
ethanoate
this part from the acid
and is named after it
Structural formulae
Although the previous structural formula are the clearest
way of showing esters, they can draw out in a
shortened form.
In this version
ethyl ethanoate
O
Either…
CH3 CH2
O
C
CH3
Or…
O
CH3 C
the acid part
has been
written first
O
CH2
CH3
 Identify the group attached to the C=O – this is from
the acid
 The group attached to the –O- is from the alcohol.
Esters Practice R-O-C-R
• Draw the condensed structure for
butyl hexanoate
Wait! What’s that smell?
ester
ethyl methanoate
3-methylbutyl ethanoate
ethyl 2-methylbutanoate
phenylmethyl ethanoate
fragrance
raspberries
pears
apples
jasmine
• Esters have strong, sweet smells.
• Their bouquet is often floral or fruity.
• This means they are used in food flavourings &
perfumes.
• Also, very good at dissolving organic compounds so
often used as solvents.
Alcohols
Fire accelerants
Drugs
OH
H3C
OH
HO
O
Ethyl Alcohol – Ethanol:
(C2H5OH), flash point 13 oC;
ignition temp. 365 oC; explosive
limits 3.5%-19.0%
Explosives
OH
OH
Glycerol or glycerine:
Used as starting material
for nitro-glycerine
4-hydroxybutanoic acid (GHB):
Date rape drug. GHB has been used in
cases of drug-related sexual assault
Dyes
OH
O
CH3
N
N
OH
BTTN :Military propellant for missiles: the mixture
can be made by co-nitration of butanetriol and
glycerol
Sudan Red G: It is considered carcinogenic and
genotoxic
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Alcohols
An alcohol contains the
hydroxyl (-OH)
functional group.
(instead of an H in that
place)
Ethanol
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Alcohols
An alcohol contains a hydroxyl group (—OH) attached to a
carbon chain.
A phenol contains a hydroxyl group (—OH) attached to a
benzene ring.
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Pearson Education, Inc.
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Cummings
water
alcohol
phenol
24
Naming Alcohols
The names of alcohols
• in IUPAC replace the -e with -ol.
• with common names use the name of the alkyl group
followed by alcohol.
Formula
IUPAC
CH4
methane
CH3─OH
methanol
CH3─CH3
ethane
CH3─CH2─OH
ethanol
Common Name
methyl alcohol
ethyl alcohol
25
Aldehydes
Drugs
O
Dyes
O
O
O
Piperonal: Precursor of
MDMA (Ecstasy: 3,4methylenedioxy-Nmethylamphetamine)
N
NH2
+
O
O
-
4-amino-3-nitrobenzaldehyde: Hair dye
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Aldehydes
An aldehyde contains a
carbonyl group (C=O),
which is a carbon atom
with a double bond to an
oxygen atom.
formaldehyde
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acetaldehyde
27
Carboxylic acids
Drugs
CH3
N
O
Benzoylecgonine (ecgonine
benzoate) is the primary
metabolite of cocaine. It is formed
in the liver by the metabolism of
cocaine
O
HO
O
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Carboxylic Acids
Carboxylic acids contain the
carboxyl group, which is a
carbonyl group attached to a
hydroxyl group.
O
║
— C—OH
Acetic acid
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29
Amides
Dyes
Yellow 13: pigment
O
CH3
CH3
NH
N
O
H3C
N
Cl
Cl
N
N
O
Drugs
CH3
NH
N
O
CH3
CH3
CH3
CH3
O
NH
CH3
CH3
Fraud between drug dealers
Lidocaine is often added to
cocaine as
a diluent because it numbs the
gums when applied,
giving the impression of higher
cocaine purity
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Amines
Drugs
Explosives
O
O
O
-
-
O
N
O
-
O
N
+
N
+
+
OH
+
O
N
O
NH
-
CH3
NH
CH3
+
O
-
+
N
O
O
-
N
O
Ephedrine: found in cold remedies, but used to
Enhance performance. Overdose can lead to death.
Similar chemical structure than methamphetamine
Hexanitrodiphenylamine: 40% part of an
explosive called hexanite; rest 60% TNT.
Obsolete explosive from WWII
Dyes
O
N
H
H
N
O
Indigo: found in foodstuff and textiles
(jeans)
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Organic compounds with CarbonNitrogen bonds
1. Amines
In amines, the functional
group is a nitrogen atom.
H
H
C —N – H or C —N —C
Methyl amine
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Dimethyl amine
32
Naming simple amines
• Simple 1º amines are named as “alkylamine”
– Examples:
• methylamine CH3NH2
• ethylamine CH3CH2NH2
• butylamine CH3CH2CH2CH2NH2
• Symmetrical 2º or 3º amines are named as
“dialkylamine” or “trialkyamine”
– Examples:
• diethylamine
(CH3CH2)2NH;
• trimethylamine (CH3)3N
R
R
NH3
R
NH
NH2
N
R
R
Ammonia
A primary amine
R
A tertuary amine
A secondary amine
Examples:
R
R
R
NH2
R
A primary amine
NH2
OH
R
R
A tertuary alkcohol
pentan-2-amine
NH2
NH
N-methylcyclohexanamine
cyclohexanamine
Amines are much more polar, than hydrocarbons, especially in acidic conditions
More biologically active
amines…
H
O
O
H
N
CH3CH2O
Cl
CH3
N
N
N
N
N
CH2CH2CH3
O
O S N
O
diazepam (Valium)
O
H2N
C OCH2CH3
benzocaine
(a topical anesthetic)
N
CH3
Sildenafil (Viagra)
Learning Check
Classify each of the following as: alcohol, ether,
aldehyde, ketone, carboxylic acid, ester, amine or
amide.
1) CH3─CH2─CH2─OH
2) CH3─O─CH2─CH3
3) CH3─CH2─NH2
O
║
4) CH3─C─OH
carboxylic acid
alcohol
ether
amine
O
║
5) CH3─C─O─CH3
ester
36