Alcohols.
Phenols. Ethers.
Prepared by ass. Medvid
I.I., ass. Burmas N. I.
Outline
1. Classification of alcohols.
2. Nomenclature of alcohols.
3. Classification of monohydric alcohols
4. Isomery of monohydroxyl alcohols
5. Physical properties of monohydroxyl alcohols
6. The methods of extraction of monohydroxyl alcohols
7. Chemical properties of monohydroxyl alcohols
8. Di-, tri- and polyhydroxyl alcohols
9. Thioalcohols
10. Ethers (simple ethers)
11. Enols
12. Aminoalcohols
13. Some of the alcohols
14. Mononuclear phenols
15. The nomenclature and isomery of mononuclear
phenols
16. The methods of extraction of mononuclear phenols
17. Physical properties of phenols
18. Chemical properties of mononuclear phenols
19. Usage of the chemical properties in the receiving of
medical drugs
20. Di-, tri- and polynuclear phenols
21. Chemical properties of di-, tri- and polynuclear phenols
22. The representatives of phenols
23. Aminophenols
24. Aromatic carboxylic acids
1. Classification of alcohols.
All alcohols, а principle, can be divided into two
broad categories i.е. aliphatic alcohols and aromatic
alcohols.
1. Aliphatic alcohols. Alcohols in which the hydroxyl
group is linked an aliphatic carbon chain are called
aliphatic alcohols.
For example,
Methyl alcohol
Methanol
Ethyl alcohol
Ethanol
Isopropyl alcohol
2-Propanol
2. Aromatic alcohols. Alcohols in which the hydroxyl group is present in
the side chain of an aromatic hydrocarbon are called aromatic For
example.
phenylmethanol
(benzyl alcohol)
2-phenylethanol
(-phenylethyl alcohol)
Alcohols are further classified as monohydric, dihydric, trihydric and
роlyhidric according as their molecules contain one, two, three, or
many hydroxyl groups respectively. For ехаmрlе,
Ethyl alcohol
(Monohydric)
1,2-Ethanediol
(Dihydric)
1,2,3-propanetriol
(Trihydric)
2. Nomenclature of alcohols.
As with most other classes of organic compounds,
alcohols can be named in several ways. Common
names are useful only for the simpler members of а
class. However, common names are widely used in
colloquial conversation and in the scientific literature.
In order to communicate freely, the student must
know common names. Since the systematic IUPAC
names are often used for indexing the scientific
literature, the student must be thoroughly familiar
with systematic names in order to retrieve data from
the literature.
I.
Тhe alkyl alcohol system. In this system of common
nomenclature, the name of an alcohol is derived by
combining the name of the alkyl group with the word
alcohol. The names are mitten as two words.
n-butyl alcohol
isobutyl alcohol
t-butyl alcohol
II. In this common system, the position of an additional
substituent is indicated by use of the Greek alphabet
rather than by numbers.
-chloroethyl alcohol
-bromobutyl alcohol
This use of the Greek alphabet is widespread in organic
chemistry and it is important to learn the first few letters, at
least through delta. Many of the letters, small and capital,
have evolved standard meanings in the mathematical and
physical sciences (for example, the number ). In organic
chemistry, the lower case letters are used more frequently
than the capital letters.
The last letter of the Greek alphabet is omega, .
Correspondingly, this letter is used to refer to difunctional
compounds when the secondary substituent is on the end
carbon of the chain.
Br(CH2)nOH -bromo alcohols
Any simple radical that has а common name may be used in
the alkyl alcohol system, with one important exception. The
grouping С6Н5 - has the special name phenyl, but the
compound C6H5OH is phenol, not phenyl alcohol.
phenol
Substituted phenols are named as derivatives of the parent compound
phenol. The reason for this difference is historical and arose from the fact
that phenol and its derivatives have many chemical properties that are
very different from those of alkyl alcohols. However, phenyl substituted
alkyl alcohols are normal alcohols and often have common names.
Examples are:
phenylmethanol
(benzyl alcohol)
2-phenylethanol
(-phenylethyl alcohol)
III. The carbinol system. In this system, the simplest
alcohol, СН3ОН, is called carbinol. More complex alcohols are
named as alkyl substituted carbinols. The names are written
as one word.
ethylmethylcarbinol
triethylcarbinol
methylphenilcarbinol
The number of carbons attached to the carbinol carbon
distinguishes primary, secondary, and tertiary carbinols. As
in the case of the alkyl halides, this classification is useful
because the different types of alcohols show important
differences in reactivity under given conditions. The carbinol
system of nomenclature has been falling into disuse in recent
years. However, it is found extensively in the older organic
chemical literature.
IUPAC rules for naming alcohols that contain а single
hydroxyl group follow.
Rule 1: Name the longest carbon' chain to which the hydroxyl group is
attached. The chain name is obtained by dropping the final -е from
the alkane name and adding the suffix -ol. – alkanols.
СН3ОН - methanol
СН3СН2ОН - ethanol
Rule 2: Number the chain starting at the end nearest the hydroxyl group,
and use the appropriate number to indicate the position of the - ОН
group. (In numbering of the longest carbon chain, the hydroxyl group
has priority over double an triple bonds, as well as over alkyl,
cycloalkyl, and halogen substituents.)
Rule 3: Name and locate any other substituents present.
Rule 4: In alcohols where the - ОН group is attached to а carbon atom in а
ring, the hydroxyl group is assumed to be on carbon 1.
In the naming of alcohols with unsaturated carbon chains, two
endings are needed: one for the double or triple bond and one
for the hydroxyl group. The -ol suffix always comes last in the
name; that is, unsaturated alcohols are named as alkenols or
alkynols.
Polyhydroxy alcohols — alcohols that possess more than one
hydroxyl group - can be names with only а slight modification
of the preceding IUPAC rules. An alcohol in which two
hydroxyl groups are present is named as а diol, one
containing three hydroxyl groups is named as а triol, and so
on. In these names for diols, triols, and so forth, the final –е
of the parent alkane name is retained for pronunciation
reasons.
1,2-Ethanediol
1,2-propanediol
1,2,3-propanetriol
3. Classification of monohydric alcohols
Monohydroxy alcohols are hydrocarbon derivatives which
contain only one group –OH connected with sp³hybridizated carbon atom.
The general formula of monohydroxy alcohols is:
The names of monohydroxy alcohols are the names of the
same hydrocarbons with added prefix –ol.
Classification of monohydric alcohols. As already mentioned,
alcohols containing one ОН group per molecule are called
monohydric alcohols. These are further classified as primary
(1'), secondary (2'), and tertiary (3') according as the ОН
group is attached to primary, secondary and tertiary carbon
atoms respectively. For example:
Ethanol
ol Primary alcohol
Isopropyl alcohol
Secondary alcohol
2-Methylpropanane-2Tertiary alcohol
4. Isomery of monohydroxyl alcohols
Monohydroxyl alcohols are characterized by structural,
geometrical and optical isomery. Structural isomery depends
on different structure of carbon chain and different locations
of –OH group.
H3C
CH2
CH2
CH2 OH
butanol-1
For unsaturated monohydroxyl alcohols structural isomery
depends on different locations of double bond too.
H2C
CH
CH2 CH2 OH
butene-3-ol-1
H3C
CH
CH
CH2
butene-2-ol-1
OH
Only unsaturated monohydroxyl alcohols are
characterized by geometrical isomery.
H3C
CH2
C
OH
H
C
H
CH2
C
H
cys-butene-2-ol-1
OH
C
H3C
H
trans-butene-2-ol-1
Optical isomery is characteristic for alcohols
which have asymmetric carbon atom in their
structure.
CH2
HO
*C
CH3
H
CH3
R-butanol-2
CH2
H
H3C
CH3
*C
OH
S-butanol-2
5. Physical properties of monohydroxyl alcohols
Saturated alcohols are colourless liquids and crystal solids with
peculiar smell. The smallest representatives of homological
row have smell of alcohol, but higher representatives have
good smell. The lower alcohols e liquids with characteristic
odors and sharp tastes. One striking feature is their relatively
high boiling points. The ОН group is roughly equivalent to а
methyl group in approximate size and polarization, but
alcohols have much higher boiling points than the
corresponding hydrocarbons; for example, compare ethanol
(mol. wt. 46, b.р.78.50) and propane (mol. wt. 44, b.р. 420). The abnormally high boiling points of alcohols are the
result of а special type of dipolar association in the liquid
phase. Both the С - О and the О - Н bonds are polar because
of the different electronegativities of carbon, oxygen, and
hydrogen. These polar bonds contribute to the substantial
dipole moments.
However, the dipole moments of alcohols are no greater than
those of corresponding chlorides.
СН3ОН,  = 1.71 D
СН3Сl, = 194 D
СН3СН3ОН,  = 1.70 D
СН3СН2Сl,  = 2.04 D
For alcohols the negative end of the dipole is out at
the oxygen lone pairs, and the positive end is close
to the small hydrogen. For hydrogen atoms bonded
to electronegative elements dipole-dipole interaction
is uniquely important and is called а hydrogen bond.
This proximity of approach is shown by bond
distance data. The O – Н bond length in alcohols is
0.96 А. The hydrogen bonded Н. . .O distance is 2.07
А, about twice as large. In fact, this distance is
sufficiently small that some hydrogen bonds may
have а significant amount of covalent or shared
electron character.
Methanol and ethanol are reasonably good solvents for
salt-like compounds. Because they are also good solvents
for organic compounds, they are used frequently for organic
reactions such as SN2 displacement reactions.
The ОН group of alcohols can participate in the
hydrogen bond network of water. The lower alcohols are
completely soluble in water. As the hydrocarbon chain gets
larger, the compound begins to look more like an alkane,
and more of the hydrogen bonds in water must be broken to
make room for the hydrocarbon chain. Since the hydrogen
bonds that are lost are not completely compensated by
bonding to the alcohol ОН, solubility decreases as the
hydrocarbon chain gets larger. А rough point of division is
four carbons to one oxygen. Above this ratio, alcohols tend
to have little solubility in water. This guideline is only
approximate because the shape of the hydrocarbon portion
is also important. t-Butyl alcohol is much more soluble than
и-butyl alcohol because the t-butyl group is more compact
and requires less room or broken water hydrogen bonds in
an aqueous solution. А similar phenomenon is seen with the
branched pentyl alcohols.
6. The methods of extraction of monohydroxyl alcohols
Alcohols can be obtained from many other classes of
compounds. Preparations from alkyl halides and from
hydrocarbons will be discussed in this section. The
following important ways of prераring alcohols will be
discussed later, as reactions of the appropriate functional
groups.
1. Hydrolysis of halogenderivatives of hydrocarbons by
heating:
CH3−CH2−Cl + NaOH → CH3−CH2−OH + NaCl
2. Hydrogenation of alkenes. This reaction runs by Markovnikov
rule.
OH
H3C
CH
CH2 + H2O
H3C
CH
CH3
3. Reduction of carbonyl compounds (aldehydes, ketones,
carboxylic acids, complex ethers):
O
H 3C
C
H
O
H3C
[H], Ni
C
Li+AlH4-
OH
O
H3C
[H]
C
O
C2H5
H3C
C
H3C
H3C
O
[H], Pt
H3C
CH2
OH
CH2 OH
H3C
CH2 OH
H3C
CH
H3C
OH
7. Chemical properties of monohydroxyl alcohols
Alcohols are classified as primary (1'), secondary (2'), or
tertiary (3'), depending on the number of carbon atoms
bonded to the carbon atom that bears the hydroxyl group. А
primary alcohol is an alcohol in which the hydroxyl-bearing
carbon atom is attached to only one other carbon atom. А
secondary alcohol is an alcohol in which the hydroxylbearing carbon atom is attached to two other carbon atoms.
А tertiary alcohol is an alcohol in which the hydroxyl-bearing
carbon atom is attached to three other carbon atoms.
Chemical reactions of alcohols often depend on alcohol class
(1', 2', or 3').
In general, alcohols (1', 2', and 3') are very flammable
substances that, when burned, produce carbon dioxide and
water. Additional important reactions of alcohols besides
combustion include
1. Intramolecular dehydration to produce alkenes
2. Intermolecular dehydration to produce an ether
3. Oxidation to produce aldehydes, ketones, and carboxylic
acids
4. Substitution reactions to produce alkyl halides
1. Alcohols have weak acidic and weak alkaline properties.
They can react with alkaline metals like acids and form
alkoxides:
2CH3CH2OH + 2Na → 2CH3CH2ONa + H2↑
2CH3CH2ONa + H2O ↔ CH3CH2OH + NaOH
2. Alcohols can react with mineral and organic acids (complex
ethers form) like alkalis:
CH3CH2OH + HONO2 ↔ CH3CH2ONO2 + HOH
O
O
H3C
CH2 CH3
C
O
H +
H3C
C
HO
O
+ H2O
CH2 CH3
3. Dehydration of alcohols. There are 2 types of dehydration:
a) Dehydration between 2 molecules:
H3C
CH2
O
H +
HO
CH2
CH3
H3C
CH2
O
CH2
CH3
b) Dehydration in the molecule (intramolecular dehydration):
H
H
H
C
C
H
OH
H
CH2
CH2 + H2O
4. Reaction with HI, HCl, HBr:
CH3CH2OH + HI → CH3CH2I + H2O
5. Oxidation
H3C
CH2
OH
[O]
-H2O
O
H3C
C
H
[O]
O
H3C
C
OH
Primary and secondary alcohols readily undergo oxidation in
the presence of mild oxidizing agents to produce
compounds that contain а carbon — oxygen double bond
(aldehydes, ketones, and carboxylic acids). А number of
different oxidizing agents can be used for the oxidation,
including potassium permanganate (КМnO4), potassium
dichromate (К2Сr2О7), and chromic acid (H2CrO4). The net
effect of the action of а mild oxidizing agent on а primary or
secondary alcohol is the removal of two hydrogen atoms
from the alcohol. One hydrogen comes from the - ОН
group, the other from the carbon atom to which the -ОН
group is attached. This Н removal generates а carbon —
oxygen double bond. The two "removed" hydrogen atoms
combine with oxygen supplied by the oxidizing agent to
give H2O.
Primary alcohol aldehyde = carboxylic acid
Secondary alcohol = ketone
Tertiary alcohol = no reaction
The general reaction for the oxidation of а primary alcohol is
Alcohol
Aldehyde
Carboxylic acid
In this equation, the symbol [O] represents the mild oxidizing agent. The
immediate product of the oxidation of а primary alcohol is an aldehyde.
Because aldehydes themselves are readily oxidized by the same oxidizing
agents that oxidize alcohols, aldehydes are further converted to
carboxylic acids. А specific example of а primary alcohol oxidation
reaction is
The three classes of alcohols behave differently toward mild
oxidizing agents. The general reaction for the oxidation of а
secondary alcohol is
Alcohol
Ketone
As with primary alcohols, oxidation involves the removal of two
hydrogen atoms. Unlike aldehydes, ketones are resistant to
further oxidation. А specific example of the oxidation of а
secondary alcohol is
Tertiary alcohols do not undergo oxidation with mild
oxidizing agents. This is because they do not have
hydrogen on the -ОН-bearing carbon atom.
CH3
C
OH
To determine any alcohol (which contain fragment
H
in the mixture of compounds it is needed to use iodoform
test. As the result yellow precipitate forms.
CH3
R
C
I
OH
NaOI or NaOH+I2
O
I
C
I+
R
H
H
iodoform
(yellow
precipitate)
C
O Na
+
8. Di-, tri- and polyhydroxyl alcohols
Dihydroxyl alcohols contain two groups –OH in the
molecule. They are called diols. There are several types of
diols.
1. α-diols (groups –OH are situated near neighboring carbon
atoms in 1,2-locations);
2. β-diols (groups –OH are situated in 1,3-locations);
3. γ-diols (groups –OH are situated in 1,4-locations) etc.
R
CH
CH
OH
OH
R1
R
CH
OH
OH
2
1
R
CH2 CH
CH
CH2
OH
CH2
CH
OH
3
R1
R1
Trihydroxyl alcohols contain three groups –
OH in the molecule. They are called triols.
The representative is glycerine:
CH2 CH
OH
OH
CH2
OH
a) preparation of di-, tri- and polyhydroxyl alcohols
1. Much of the chemistry of diols—compounds that bear two
hydroxyl groups—is analogous to that of alcohols. Diols
may be prepared, for example, from compounds that
contain two carbonyl groups, using the same reducing
agents employed in the preparation of alcohols. The
following example shows the conversion of a dialdehyde to
a diol by catalytic hydrogenation. Alternatively, the same
transformation can be achieved by reduction with sodium
borohydride or lithium aluminum hydride.
2. Since osmium tetraoxide is regenerated in this step, alkenes
can be converted to vicinal diols using only catalytic
amounts of osmium tetraoxide, which is both toxic and
expensive. The entire process is performed in a single
operation by simply allowing a solution of the alkene and
tert-butyl hydroperoxide in tert-butyl alcohol containing a
small amount of osmium tetraoxide and base to stand for
several hours.
Overall, the reaction leads to addition of two hydroxyl groups to the
double bond and is referred to as hydroxylation. Both oxygens of the
diol come from osmium tetraoxide via the cyclic osmate ester. The
reaction of OsO4 with the alkene is a syn addition, and the conversion of
the cyclic osmate to the diol involves cleavage of the bonds between
oxygen and osmium. Thus, both hydroxyl groups of the diol become
attached to the same face of the double bond; syn hydroxylation of the
alkene is observed.
3. To extract glycerine it is necessary to use next reaction:
CH2
Cl
KOH
CH
Cl +
CH2
Cl
CH2
OH
KOH
CH
OH + 3KCl
KOH
CH2
OH
b) Chemical properties of di-, tri- and polihydroxyl alcohols
1. Reaction with alkaline metals
2
2
CH2
OH
+ 2Na
CH2
OH
CH2
ONa
+ 2Na
CH2
OH
2
2
CH2
ONa
+ H2
CH2
OH
CH2
ONa
CH2
ONa
+ H2
2. Reaction with Cu(OH)2
CH2
OH
2
CH2
H
OH
+ Cu(OH)2
H2C
H2C
O
O
Cu
O
O
H
blue colour
CH2
CH2
+ 2H2O
3. Reaction with HI, HCl, HBr:
CH2
OH
CH2
+ HCl
CH2
4.
OH
CH2
Cl
OH
+ H2O
Formation of simple and complex ethers (reaction with
monohydroxy alcohols and organic acids):
CH2 OH
CH2 OH
+ HO
H2C
CH2
CH3
CH2
O
CH2
CH3
+ H2O
OH
incomplete simple ether
1
CH2
CH2
O
OH
CH2
CH2
CH3
+ HO
H2C
CH3
CH2
O
O
CH2
CH2
CH3
CH3
complete simple ether
+ H2O
O
CH2
CH2
O
OH
OH
C
HO
+
CH2
CH3
CH2
O
C
CH3
+ H2O
OH
incomplete complex ether
2
O
O
CH2
CH2
O
C
O
CH3
+ HO
OH
C
CH2
CH3
CH2
O
O
C
C
CH3
CH3
O
complete complex ether
5. Reaction with mineral acids:
CH2
OH
CH2
OH
CH2
O
CH2
OH
+ HONO2
NO2
+ HONO2
CH2
CH2
O
NO2
+ H 2O
OH
CH2
CH2
O
O
NO2
NO2
+ H2O
+ H2O
6. Oxidation by KMnO4
O
CH2
OH
CH2
OH
[O]
C
OH
C
OH
O
7. Dehydration
OH
HO
H2C
O
CH2
+
H2C
CH2
OH
HO
H2SO4, t H2C
CH2
H2C
CH2
+ 2H2O
O
dioxane
CH2
OH
CH2
CH2
CH2 H SO , t H2C
2
4
OH
CH2
H2C
CH2
O
+ H2O
8. Polycondensation
HO H2C CH2 OH + HO H2C CH2 OH
H2SO4
HO H2C CH2 O H2C CH2 OH
9. Diols react intramolecularly to form cyclic ethers when a fivemembered or sixmembered ring can result.
9. Thioalcohols
Thioalcohols are compounds which contain aliphatic
(CnH2n+1) and mercaptane (−SH) groups. Thiols are given
substitutive IUPAC names by appending the suffix -thiol to
the name of the corresponding alkane, numbering the chain
in the direction that gives the lower locant to the carbon
that bears the −SH group.
The preparation of thiols involves nucleophilic substitution of
the SN2 type on alkylhalides and uses the reagent thiourea
as the source of sulfur. Reaction of the alkyl halide with
thiourea gives a compound known as an isothiouronium salt
in the first step. Hydrolysis of the isothiouronium salt in
base gives the desired thiol (along with urea):
Both steps can be carried out sequentially without isolating
the isothiouronium salt.
To extract thioalcohols it is necessary to use next
reactions:
1. C2H5Cl + NaSH → C2H5SH + NaCl
2. C2H5OH + Na2S → C2H5SH + H2O
Physical properties of thiols
When one encounters a thiol for the first time, especially a
low-molecular-weight thiol, its most obvious property is its
foul odor. Ethanethiol is added to natural gas so that leaks
can be detected without special equipment—your nose is so
sensitive that it can detect less than one part of ethanethiol
in 10,000,000,000 parts of air! The odor of thiols weakens
with the number of carbons, because both the volatility and
the sulfur content decrease. 1-Dodecanethiol, for example,
has only a faint odor. The S-H bond is less polar than the O-H
bond, and hydrogen bonding in thiols is much weaker than
that of alcohols. Thus, methanethiol (CH3SH) is a gas at
room temperature (bp 6°C), and methanol (CH3OH) is a
liquid (bp 65°C).
1.
Chemical properties of thiols:
Thiols can react with ions of alkaline and heavy metals (this
property of thiols is used in medicine at the poisoning by
heavy metals):
C2H5SH + NaOH → C2H5S−Na+ + H2O
2C2H5SH + Hg²+ → (C2H5S)2Hg + 2H+
2. They can react with alkenes (peroxides are catalysts):
H3C
S
H + H2C
CH
CH3
H3C
S
CH2 CH2 CH3
3. Reaction with organic acids:
O
C2H5 SH + H3C
C
O
H3C
OH
C
+ H2O
S
C2H5
4. Oxidation
C2H5 S
H + [O] + H
S
CH3
C2H5 S
S
CH3 + H2O
10. Ethers (simple ethers)
The general formula of simple ethers is:
R−O−R1
The radicals can be similar or different.
Ethers are named, in substitutive IUPAC nomenclature, as
alkoxy derivatives of alkanes. Functional class IUPAC names
of ethers are derived by listing the two alkyl groups in the
general structure ROR1 in alphabetical order as separate
words, and then adding the word “ether” at the end. When
both alkyl groups are the same, the prefix di- precedes the
name of the alkyl group.
Physical properties of ethers
It is instructive to compare the physical properties of ethers
with alkanes and alcohols. With respect to boiling point,
ethers resemble alkanes more than alcohols. With respect to
solubility in water the reverse is true; ethers resemble
alcohols more than alkanes.
In general, the boiling points of alcohols are unusually high
because of hydrogen bonding . Attractive forces in the liquid
phases of ethers and alkanes, which lack - OH groups and
cannot form intermolecular hydrogen bonds, are much
weaker, and their boiling points lower. These attractive forces
cause ethers to dissolve in water to approximately the same
extent as comparably constituted alcohols. Alkanes cannot
engage in hydrogen bonding to water.
The methods of extraction of ethers:
1. From alkoxides:
CH3CH2ONa + CH3I → CH3CH2OCH3 + NaI
2. Dehydration of alcohols (dehydration between 2
molecules):
H3C CH2 O
H +
HO CH2 CH3
H3C CH2 O CH2 CH3
Chemical properties of ethers
1. Reaction with concentrated mineral acids (formation of
oxonium salts):
H3C
CH2
O
CH3 + HONO2
+
H 3C
CH2
O
CH3
-
NO3
H
2. A second dangerous property of ethers is the ease with
which they undergo oxidation in air to form explosive
peroxides. Air oxidation of diethyl ether proceeds according
to the equation
The reaction follows a free-radical mechanism and gives a
hydroperoxide, a compound of the type ROOH.
Hydroperoxides tend to be unstable and shock-sensitive. On
standing, they form related peroxidic derivatives, which are
also prone to violent decomposition. Air oxidation leads to
peroxides within a few days if ethers are even briefly
exposed to atmospheric oxygen. For this reason, one should
never use old bottles of dialkyl ethers, and extreme care
must be exercised in their disposal.
3. Reaction with HI
CH3−O−CH3 + HI → CH3−OH + CH3I
The mechanism for the cleavage of ethers by hydrogen halides,
using the reaction of diethyl ether with hydrogen bromide as
an example.
Step 1: Proton transfer to the oxygen of the ether to give a
dialkyloxonium ion.
Step 2: Nucleophilic attack of the halide anion on carbon of
the dialkyloxonium ion. This step gives one molecule of
an alkyl halide and one molecule of an alcohol.
Step 3 and Step 4: These two steps do not involve an ether
at all. They correspond to those in which
an alcohol is converted to an alkyl halide .
11. Enols
Enols (also known as alkenols) are alkenes with a hydroxyl group affixed to
one of the carbon atoms composing the double bond. Enols and carbonyl
compounds (such as ketones and aldehydes) are in fact isomers; this is
called keto-enol tautomerism:
The enol form is shown above on the left. It is usually
unstable, does not survive long, and changes into the keto
(ketone) form shown on the right. This is because oxygen is
more electronegative than carbon and thus forms stronger
multiple bonds. Hence, a carbon-oxygen (carbonyl) double
bond is more than twice as strong as a carbon-oxygen single
bond, but a carbon-carbon double bond is weaker than two
carbon-carbon single bonds.
The name of enols systematic nomenclature IUPAC
form the name alkene to which is added the suffix-ol:
CH2=CH-OH
CH2=CH-CH2-OH
ethenol, vinyl alcohol
Propenol-1(unsaturated alcohol)
Hydration of acetylene as the intermediate substance
is formed vinyl alcohol (enol), which isomerization in
acetic aldehyde.
H2O,Hg²+,H+
C2H2
CH2=CH-OH
This property of enols characterizes the rule of
Eltekov-Erlenmeyer. - Compounds in which the
hydroxyl group located at carbon atoms that
forms a fold communication, unstable and
isomerization of carbonyl compounds aldehydes and ketones
Unlike enols, and their simples and composites esters
are stable. They do not contain the rolling of the
hydrogen atom and under normal conditions do not
form carbonyl compounds. Yes, there are esters of
vinyl alcohols, such as vinyl acetate, a which produce
the reaction of acetic acid to join acetylene.
CH3-COOH + C2H2
CH3-C(O)-O-CH=CH2
12. Aminoalcohols
Amino alcohols are organic compounds that contain
both an amine functional group and an alcohol
functional group.
NH2-CH2-CH2-OH
N(C2H5)-CH2-CH2-OH
2-aminoethanol
2-N,N- diethylaminoethanol
If the molecule of amino alcohol contains the in its
composition two or three hydroxyalkylnes groups, through
the combination of nitrogen atom, in this case, the basis
takes the name amine.
OH-CH2-CH2-NH-CH2-CH2-OH
di (β-oxyethyl) amine, or di (2-hydroxyethyl) amine
The methods of extraction of aminoalcohols
1. Accession of ammonia or amines to the α-oxyses.
CH2-CH2 + NH3
NH2-CH2-CH2-OH
O
2. Reduction of nithroarenes.
CH3-CH(NO2)-CH2-OH + 3H2
CH3-CH(NH3)-CH2-OH + 2H2O
Chemical properties of aminoalcohols
Aminoalcohols show properties as alcohols and
amines. As a basis aminoalcohols form salts with
mineral acids.
OH-CH2-CH2-NH2 + HCl
OH-CH2-CH2-NH3Cl¯
Ethanolamine, also called 2-aminoethanol or
monoethanolamine (often abbreviated as ETA or
MEA), is an organic chemical compound that is both
a primary amine (due to an amino group in its
molecule) and a primary alcohol (due to a hydroxyl
group). Like other amines, monoethanolamine acts
as a weak base.
Monoethanolamine is produced by reacting
ethylene oxide with aqueous ammonia; the reaction
also produces diethanolamine and triethanolamine.
The ratio of the products can be controlled by
changing the stoichiometry of the reactants.
13. Some of the alcohols
Methyl alcohol (Methanol). Methyl alcohol, with one carbon
atom and one — ОН group, is the simplest alcohol. This
colorless liquid is а good fuel for internal combustion
engines. Since 1965 all racing cars at the Indianapolis
Speedway have been fueled with methyl alcohol. (Methyl
alcohol fires are easier to put out than gasoline fires,
because water mixes with and dilutes methyl alcohol.)
Methyl alcohol also has excellent solvent properties, and it is
the solvent of choice for paints, shellacs, and varnishes.
Methyl alcohol is sometimes called wood alcohol,
terminology that draws attention to an early method for its
preparation — the heating of wood to а high temperature in
the absence of air. Today, almost all methyl alcohol is
produced via the reaction between H2 and СО. Drinking
methyl alcohol is dangerous. Within the human body,
methyl alcohol is oxidized by the liver enzyme alcohol
dehydrogenase to the toxic metabolites formaldehyde and
formic acid. Formaldehyde is toxic to the eyes and can
cause blindness (temporary or permanent). Formic acid
causes acidosis. Ingesting as little as 1 oz (30 ml.) of methyl
alcohol can cause optic nerve damage.
Ethyl alcohol (Ethanol), the two-carbon monohydroxy alcohol, is the
alcohol present in alcoholic beverages and is commonly referred to as simply
alcohol or drinking alcohol. Like methyl alcohol, ethyl alcohol is oxidized in
the human body by the liver enzyme alcohol dehydrogenase. Acetaldehyde,
the first oxidation product, is largely responsible for the symptoms of
hangover. The odors of both acetaldehyde and acetic acid are detected on
the breath of someone who has consumed а large amount of alcohol. Ethyl
alcohol oxidation products are less toxic than these of methyl alcohol. Longterm excessive use of ethyl alcohol may cause undesirable effects such as
cirrhosis of the liver, loss of memory, and strong physiological addiction.
Links have also been established between certain birth defects and the
ingestion of ethyl alcohol by women during pregnancy (fetal alcohol
syndrome). Ethyl alcohol can be produced by yeast fermentation of sugars
found in plant extracts. The synthesis of ethyl alcohol in this manner, from
grains such as corn, rice, and barley, is the reason why ethyl alcohol is often
called grain alcohol. Denatured alcohol is ethyl alcohol that has been
rendered unfit to drink by the addition of small amounts of toxic substances
(denaturing agents). Almost all of the ethyl alcohol used for industrial
purposes is denatured alcohol. Most ethyl alcohol used in industry is
prepared from ethene via а hydration reaction The reaction produces а
product that is 95% alcohol and 5% water. In applications where water
does interfere with use, the mixture is treated with а dehydrating agent to
produce 100% ethyl alcohol. Such alcohol, with all traces of water removed,
is called absolute alcohol.
Isopropyl alcohol (2-propanol) is one of
two three-carbon monohydroxy alcohols; the other
is propyl alcohol. А 70% isopropyl alcohol — 30%
water solution marketed as rubbing alcohol.
Isopropyl alcohol's rapid evaporation rate creates а
dramatic cooling effect when it is applied to the
skin, hence its use for alcohol rubs to combat high
body temperature. Isopropyl alcohol has а bitter
taste. Its toxicity is twice that of ethyl alcohol but
causes few fatalities because it often induces
vomiting and thus doesn' t stay down long enough
to kill you. In the body it is oxidized to acetone.
Large amounts, about 150 mL, of ingested
isopropyl alcohol can be fatal; death occurs from
paralysis of the central nervous system.
Ethylene glycol (1,2-ethanediol) and propylene
glycol (1,2-propanediol) are the two simplest alcohols
possessing two – ОН groups. Besides being diols, they are also
classified as glycols. А glycol is а diol in which the two - ОН
groups are on adjacent carbon atoms. Both of these glycols are
colorless, odorless, high-boiling liquids that are completely
miscible with water. Their major uses are as the main
ingredient in automobile "year-round" antifreeze and airplane
"de-icers" and as а starting material for the manufacture of
polyester fibers. Ethylene glycol is extremely toxic when
ingested. In the body, liver enzymes oxidize it to oxalic acid.
Oxalic acid, as а calcium salt, crystallizes in the kidneys, which
leads to renal problems. On the other hand, propylene glycol is
essentially nontoxic and has been used as а solvent for drugs.
Like ethylene glycol, it is oxidized by liver enzymes; however,
pyruvic acid, its oxidation product, is а compound normally
found in the human body, being an intermediate in
carbohydrate metabolism.
Glycerol (1,2,3-propanetriol) is а clear, thick liquid that
has the consistency of honey. Its molecular structure involves
three ОН groups on three different carbon atoms.
14. Mononuclear phenols
Phenols are compounds that have a hydroxyl
group bonded directly to a benzene or
benzenoid ring. The parent compound of this
group, C6H5OH, called simply phenol, is an
important industrial chemical. Many of the
properties of phenols are analogous to those
of alcohols, but this similarity is something of
an oversimplification. Like arylamines,
phenols are difunctional compounds; the
hydroxyl group and the aromatic ring interact
strongly, affecting each other’s reactivity.
This interaction leads to some novel and
useful properties of phenols.
15. The nomenclature and isomery of mononuclear
phenols
Numbering of the ring begins at the hydroxylsubstituted carbon and proceeds in the direction that
gives the lower number to the next substituted
carbon. Substituents are cited in alphabetical order.
HO
N
H
C CH3
C2H5O
C2H5O
C CH3
O
O
Paracetamol, (N-acetyl-p-aminophenol
p-hydroxyacethanilide),
N
H
Phenacetin (p-еthoxyacethanilide)
NH2
Phenetidine (p-ethoxyaniline)
The structural isomery of phenols is obtained by
different locations of radicals and structural changes
of radicals.
H3C H2C H2C
4-propylphenol
OH
H3C
HC
OH
H 3C
4-isopropylphenol
16. The methods of extraction of monohydric
phenols
1.Natural
tar)
C 6 H 5 -OHsources
+ NaOH(from coal C
6 H 5 -ONa + H 2 O
Phenolyath
sodium
С6H5-ONa + H2O + CO2
C6H5-OH + NaHCO3
2. The synthesis from arenes
SO 3 H
OH
4NaOH
SO 3 H
4000 C
+ 2Na2 SO3 + 2H2 O
OH
3. Cumol (isopropyl toluene) synthesis
C 6H 5
H 3C
C
C 6H 5
H
O 2 (OH-)
H 3C
1300 C
C
CH 3
..
O
..
..
O
..
H+
H
H 3C
Acetone
4. The extraction from diazonium salts
_
+
OH
HOH
+ N2 + HCl
R
R
5. The substitution of halogen atom to –OH group
NH2. HCl
OH
3HOH
HCl . H2 N
NH2 . HCl
+ 3NH4 Cl
HO
Cl
OH
OH
NO 2
NO 2
NaOH, H2 O
-HCl
NO 2
+ C 6 H5 OH
O
Cumol
N Cl
CH 3
650 C
CH 3
+
N
C
NO 2
Phenol
17. Physical properties of phenols
All phenols have peculiar smell. They are colorless compounds but oxygen
from the air can cause brown colour of phenols (oxidation). They solve in
water badly. The physical properties of phenols are strongly influenced by
the hydroxyl group, which permits phenols to form hydrogen bonds with
other phenol molecules and with water . Thus, phenols have higher
melting points and boiling points and are more soluble in water than
arenes and aryl halides of comparable molecular weight. Table 24.1
compares phenol, toluene, and fluorobenzene with regard to these
physical properties. Some ortho-substituted phenols, such as onitrophenol, have significantly lower boiling points than those of the meta
and para-isomers. This is because the intramolecular hydrogen bond that
forms between the hydroxyl group and the substituent partially
compensates for the energy required to go from the liquid state to the
vapor. Electron delocalization in phenoxide is represented by resonance
among the structures:

Substance

..
O
..

H
H3 C
CH2


..
O
H
..
lС-О, nm
0,140
0,144
, D
1,53
1,66
, сm-1
1230
1050-1200
 < 
18. Chemical properties of mononuclear phenols
1. Acidic properties:
C6H5−OH + NaOH ↔ C6H5−ONa + H2O
C6H5−ONa + H2O ↔ C6H5−OH + NaOH
OH
NO
O N
2
H3 C
O
2
H
NO
2
Picric acid
O
N
-O
O
+
O
N
H
-O
O + H+
2. Forming of simple and complex ethers:
C6H5−ONa + C2H5−Br ↔ C6H5−O−C2H5 + NaBr
ethylphenyl ether
C6H5−ONa + CH3−COCl ↔ C6H5−O−CO−CH3 + NaCl
phenylacetate
3. Halogenations. (The reaction that underlies qualitative and
quantitative analysis of phenol and its derivatives)
OH
OH
Br
Br
+ 3Br2
O
Br
Br
+Br2
-3Br2
-HBr
Br
Br
Br
white precipitate
yellow precipitate
4. Nitrating
OH
OH
OH
NO2
HNO3 (H2O)
+
t=25
2
+ 2H2O
o-nitrophenol
NO2
p-nitrophenol
5. Sulphating
OH
OH
OH
H2SO4
t=-20
SO3H
o-hydroxybenzylsulphoacid
H2SO4
t=+100
HO3S
p-hydroxybenzylsulphoacid
6. Alkylation and acylation (the catalysts are H2SO4, H3PO4,
BF3:
OH
OH
OH
CH3
2
+ 2 H3C
OH
+ 2H2O
+
CH3
OH
OH
O
2
+ 2 H3C
C
OH
O
C
CH3
+ 2H2O
+
OH
O
C
CH3
7. Azoaccession
+
N
NaOH
_
N Cl
OH
+
N N
-NaCl, -H2O
R
OH
R
8. The synthesis of phenolocarboxylic acids:
_
O Na
+
OH
OH
O
+
C
COONa
125 0C, p
COOH
HCl
-NaCl
O
salicylic acid
sodium salicylate
9. To determine mono-, di-, tri- and polynuclear phenols it is necessary to do
the reaction with FeCl3. As the result of this reaction color complex
compounds form.
H
OC H
H
6
C6 H5
6C6H5OH + FeCl3
5
O:
:O
C6 H5
Fe
-3HCl
C6 H5
O
..
O
H
O
C6 H5
C6 H5
The coloration of phenols in reaction with FeCl3
Name of phenol
Color products of
reaction with FeCl3
pyrocatechol
green color
resorcinol
blue color
hydroquinone
pyrogallol
green color that turns to
yellow color
red color
phloroglucinol
dark violet color
10. Oxidation of phenols. Quinones.
Phenols are more easily oxidized than alcohols, and a large
number of inorganic oxidizing agents have been used for this
purpose. The phenol oxidations that are of the most use to
the organic chemist are those involving derivatives of 1,2benzenediol (pyrocatechol) and 1,4-benzenediol
(hydroquinone). Oxidation of compounds of this type with
silver oxide or with chromic acid yields conjugated dicarbonyl
compounds called quinones.
Quinones are compounds having a fully conjugated cyclic
dione structure, such as that of benzoquinones, derived from
aromatic compounds by conversion of an even number of –
CH= groups into –C(=O)– groups with any necessary
rearrangement of double bonds (polycyclic and heterocyclic
analogues are included). Benzoquinone, sometimes referred
to simply as "quinone", is either of the two isomers of
cyclohexadienedione. These compounds have the molecular
formula C6H4O2. Orthobenzoquinone is the 1,2-dione,
whereas parabenzoquinone is the 1,4-dione.
Orthobenzoquinone is the oxidized form of catechol (1,2dihydroxybenzene), while parabenzoquinone is the oxidized
form of hydroquinone. An acidic potassium iodide solution
reduces a solution of benzoquinone to hydroquinone, which is
oxidized back with a solution of silver nitrate.
19. Usage of the chemical properties in the receiving of
medical drugs
А) Synthesis of thymol:
CH 3
CH 3
H 2SO 4
HSO 3
(CH 3) 2CHOH
OH
CH 3
HSO 3
OH
H 3C
CH 3
H2O
OH
H 3C
OH
CH 3
thymol
CH 3
B) Synthesis of paracetamol (pyretic and analgesic means):
NO 2 2H
2
NH-OH H 2SO 4
NH 2 (CH CO) O
3
2
HO
NHCOCH 3
HO
p-acetylaminophenol,
paracetamol
C) Synthesis of phenethidine and phenacetine (pyretic and
anti-neuralgic means)
C 2H 5Br
NaOH
HO
NH 2
NaO
NH 2
-NaBr
C 2H 5O
NH 2
phenethidine
(CH 3CO) 2O
C 2H 5O
NHCOCH 3
phenacetine
20. Di-, tri- and polynuclear phenols
OH
OH
OH
OH
naphthol
anaphthol
pyrocatechol
O H
O H
O H
O H
H O
pyrogallol
OH
hydroquinone
O H
H O
OH
O H
O H
phloroglucinol
hydroxyhydroquinone
21. Chemical properties of di-, tri- and polynuclear
phenols
Chemical properties of di-, tri- and polynuclear phenols are
similar to chemical properties of mononuclear phenols. But
they have some peculiarities.
1. Acidic properties of polynuclear phenols are stronger than
acidic properties of mononuclear phenols. Polynuclear
phenols can react with alkaline and heavy metals:
O
OH
(CH3COO)2Pb
Pb
-2CH3COOH
OH
O
2. Oxidation. polynuclear phenols oxidize more easily
than mononuclear phenols.
O
OH
Ag2O, ether
Na2SO4
OH
pyrocatechol
O
o-benzoquinone
22. The representatives of phenols
OH
phenol. Colourless crystals, it has antiseptic properties.
It is toxic and can cause combustions. It is used in the
manufacture of dyes, medicines.
OH
CH3
o-, m- and p-cresols. They are
disinfectant compounds and used in
veterinary medicine.
OH
H 3C
CH
CH3
thymol. Colourless crystals. It is used in
medicine as antiseptic and antihelminthic mean.
CH3
OH
NO2
O2N
picric acid. Yellow crystals. It is used in
pharmaceutical analysis.
NO2
OH
α-naphtol. Yellowish crystals. It is used in the
manufacture of dyes, medicines.
OH
OH
O
pyrocatechol. Colourless
crystals. It can oxidize to
(CH3COO)2Pb
brown colour in the open
Pb air. It has antiseptic properties.
-2CH3COOH
It take part in the synthesis of adrenalin.
OH
HO
β-naftol. White powder. It is used in the manufacture of
dyes, medicines and in pharmaceutical analysis.
OH
O
resorcinol. Colourless crystals. It is used in the
manufacture of dyes. It is antiseptic compound by skin
diseases (the ointments contain it).
OH
HO
pyrogallol. White crystals. It can oxidize to brown
colour in the light. It is used in the manufacture of
dyes.
OH
HO
OH
phloroglucinol . Colourless crystals. It is used in
pharmaceutical analysis.
OH
HO
CH
OH
HO
CH2
NH
CH3
adrenalin. Colourless crystals. It is a hormone of
catecholamines, it is produced by inner cerebral
part of paranephroses. Adrenalin takes part in
regulation of carbohydrate metabolism and
lipometabolism. It causes narrowing of little blood
vasculars, rising of arterial pressure, it can stimulate
of heart activity.
23. Aminophenols
Aminophenols are aromatic compounds that
contain phenyl radical, −OH group and
aminogroup. There are o-, m- and paminophenols.
OH
OH
OH
NH2
NH2
o-aminophenol
m-aminophenol
NH2
p-aminophenol
The methods of extraction of aminophenols
1.
The reduction of nitrophenols:
OH
OH
NH2
NO2
3H2
2.
+ 2H2O
o-aminophenol
o-nitrophenol
Reaction of dihydroxic phenols with ammonium:
OH
OH
t
+ NH3
+ H2O
OH
NH2
pyrocatechol
o-aminophenol
3. The reduction of nitrobenzene:
NO2
N
H2
NH
nitrozobenzene
NH2
OH
H2SO4
H2
-H2O
nitrobenzene
O
HO
phenylhydroxylamine
p-aminophenol
Chemical properties: aminophenols have properties of
phenols and aromatic amines.
The derivatives of aminophenols are medical
preparations:
It is antipyretic, antiinflammatory mean. It is
used for the treatment of
headache, toothache, high
temperature.
O
HO
NH
C
CH3
p-acetylaminophenol
(paracetamol)
O
H3C
H2C
O
NH
C
CH3
phenacetin
It is antipyretic and antineuralgic mean
24. Aromatic carboxylic acids
Aromatic carboxylic acids are the derivatives of hydrocarbons
that contain carboxyl group (-COOH) and benzyl radical.
O
O
H2C
H3C
C
C
OH
OH
3-ethylbenzoic acid
H 3C
HNO 3
benzoic acid
H 3C
NO 2
C 2H 5OH, H2SO 4
[O]
O 2N
COOH
[H]
O 2N
COOCH 5
2
H 2N
COOCH
2 5
anesthysine
COONa
COOH
OH
NH 2
Anthranilic acid
NH2
Sodium p-aminosalicylate
H 2N
COOCH 2CH 2N(C 2H 5) 2 . HCl
novocaine
The key compound in the synthesis of aspirin,
salicylic acid, is prepared from phenol by a process
discovered in the nineteenth century by the German
chemist Hermann Kolbe. In the Kolbe synthesis, also
known as the Kolbe–Schmitt reaction, sodium
phenoxide is heated with carbon dioxide under
pressure, and the reaction mixture is subsequently
acidified to yield salicylic acid:
OH
C
COONa POCl 3, C 6H 5ONa
NaHCO 3
O
OH
OC 6H 5
-CO 2, -H 2O
-NaCl, -NaPO 3
Phenylsalicylate, salol
Sodium salicylate
O
OH
COOH
O
(CH 3CO) 2O
C
NH 2
CH 3
COOH
-C 6H 5OH
- CH 3COOH
Salicylic acid
Acetylsalicylic acid,
aspirin
CH 3OH
-H 2O
OH
(H 2SO 4)
OH
OH
COOCH 3
Methylsalicylate
O
OH
C
NH 3
O
C
NH 2
NH
Salicylamide
Oxaphenamide
OH
Salicylic acid (from the Latin word for the willow tree, Salix, from whose
bark it can be obtained) is a beta hydroxy acid. This colorless crystalline
organic acid is widely used in organic synthesis and functions as a plant
hormone. It is derived from the metabolism of salicin. In addition to
being a compound that is chemically similar to but not identical to the
active component of aspirin (acetylsalicylic acid), it is probably best
known for its use in anti-acne treatments. The salts and esters of salicylic
acid are known as salicylates.
4-Aminosalicylic acid, commonly known as PAS, is an
antibiotic used to treatment of tuberculosis.
COOH
OH
OH
OH
CO2 , KOH
NH3
-H2 O
OH
NH 2
NH 2
PAS
The best known aryl ester is O-acetylsalicylic acid, better
known as aspirin. It is prepared by acetylation of the phenolic
hydroxyl group of salicylic acid:
Aspirin possesses a number of properties that make it an
often-recommended drug. It is an analgesic, effective in
relieving headache pain. It is also an antiinflammatory agent,
providing some relief from the swelling associated with
arthritis and minor injuries. Aspirin is an antipyretic
compound; that is, it reduces fever. Each year, more than 40
million lb of aspirin is produced in the United States, a rate
equal to 300 tablets per year for every man, woman, and
child.
Thank you for attention!