Phenol physical properties. Phenols

One-, two-, and three-atomic phenols are distinguished depending on the number of OH groups in the molecule (Fig. 1)

Rice. 1. ONE-, BI- AND TRICHATIC PHENOLS

In accordance with the number of condensed aromatic rings in the molecule, they are distinguished (Fig. 2) into phenols themselves (one aromatic ring - benzene derivatives), naphthols (2 condensed rings - naphthalene derivatives), anthranols (3 condensed rings - anthracene derivatives) and phenanthroles (Fig. 2).

Rice. 2. MONO- AND POLYNUCLEAR PHENOLS

Nomenclature of alcohols.

For phenols, trivial names that have developed historically are widely used. The names of substituted mononuclear phenols also use prefixes ortho-,meta- And pair -, used in the nomenclature of aromatic compounds. For more complex compounds, the atoms that are part of the aromatic rings are numbered and the position of the substituents is indicated using digital indices (Fig. 3).

Rice. 3. NOMENCLATURE OF PHENOLS. Substituting groups and corresponding digital indices are highlighted in different colors for clarity.

Chemical properties of phenols.

The benzene ring and the OH group, combined in a phenol molecule, influence each other, significantly increasing each other's reactivity. The phenyl group absorbs a lone pair of electrons from the oxygen atom in the OH group (Fig. 4). As a result, the partial positive charge on the H atom of this group increases (indicated by the d+ symbol), the polarity of the O–H bond increases, which manifests itself in an increase in the acidic properties of this group. Thus, compared to alcohols, phenols are stronger acids. A partial negative charge (denoted by d–), transferring to the phenyl group, is concentrated in positions ortho- And pair-(relative to the OH group). These reaction points can be attacked by reagents that gravitate toward electronegative centers, so-called electrophilic (“electron-loving”) reagents.

Rice. 4. ELECTRON DENSITY DISTRIBUTION IN PHENOL

As a result, two types of transformations are possible for phenols: substitution of a hydrogen atom in the OH group and substitution of the H-atomobenzene ring. A pair of electrons of the O atom, drawn to the benzene ring, increases the strength of the C–O bond, therefore reactions that occur with the rupture of this bond, characteristic of alcohols, are not typical for phenols.

1. Reactions of substitution of a hydrogen atom in the OH group. When phenols are exposed to alkalis, phenolates are formed (Fig. 5A), catalytic interaction with alcohols leads to ethers (Fig. 5B), and as a result of reaction with anhydrides or acid chlorides of carboxylic acids, esters are formed (Fig. 5C). When interacting with ammonia (increased temperature and pressure), the OH group is replaced by NH 2, aniline is formed (Fig. 5D), reducing reagents convert phenol into benzene (Fig. 5E)

2. Reactions of substitution of hydrogen atoms in the benzene ring.

During halogenation, nitration, sulfonation and alkylation of phenol, centers with increased electron density are attacked (Fig. 4), i.e. replacement takes place mainly in ortho- And pair- positions (Fig. 6).

With a deeper reaction, two and three hydrogen atoms are replaced in the benzene ring.

Of particular importance are the condensation reactions of phenols with aldehydes and ketones; essentially, this is an alkylation that occurs easily and under mild conditions (at 40–50 ° C, an aqueous medium in the presence of catalysts), with the carbon atom in the form of a methylene group CH 2 or a substituted methylene group (CHR or CR 2) is inserted between two phenol molecules. Often such condensation leads to the formation of polymer products (Fig. 7).

Diatomic phenol (trade name bisphenol A, Fig. 7) is used as a component in the production of epoxy resins. The condensation of phenol with formaldehyde underlies the production of widely used phenol-formaldehyde resins (phenoplasts).

Methods for obtaining phenols.

Phenols are isolated from coal tar, as well as from the pyrolysis products of brown coal and wood (tar). The industrial method for producing phenol C6H5OH itself is based on the oxidation of the aromatic hydrocarbon cumene (isopropylbenzene) with atmospheric oxygen, followed by the decomposition of the resulting hydroperoxide diluted with H2SO4 (Fig. 8A). The reaction proceeds with high yield and is attractive in that it allows one to obtain two technically valuable products at once - phenol and acetone. Another method is the catalytic hydrolysis of halogenated benzenes (Fig. 8B).

Rice. 8. METHODS FOR OBTAINING PHENOL

Application of phenols.

A phenol solution is used as a disinfectant (carbolic acid). Diatomic phenols - pyrocatechol, resorcinol (Fig. 3), as well as hydroquinone ( pair- dihydroxybenzene) are used as antiseptics (antibacterial disinfectants), added to tanning agents for leather and fur, as stabilizers for lubricating oils and rubber, as well as for processing photographic materials and as reagents in analytical chemistry.

Phenols are used to a limited extent in the form of individual compounds, but their various derivatives are widely used. Phenols serve as starting compounds for the production of various polymer products - phenolic resins (Fig. 7), polyamides, polyepoxides. Numerous drugs are obtained from phenols, for example, aspirin, salol, phenolphthalein, in addition, dyes, perfumes, plasticizers for polymers and plant protection products.

Mikhail Levitsky

Acid-base properties. The acidity of phenols is much higher (by 5-6 orders of magnitude) than the acidity of alcohols. This is determined by two factors: the greater polarity of the O-H bond due to the fact that the lone electron pair of the oxygen atom is involved in conjugation with the benzene ring (the hydroxyl group is a strong donor according to the +M effect), and significant stabilization of the resulting phenolate ion due to delocalization of the negative charge with the participation of the aromatic system:

Unlike alkanols, phenols, when exposed to alkalis, form salts - phenolates, soluble in aqueous solutions of alkalis (pH > 12). However, phenols are poorly soluble in aqueous solutions of alkali metal bicarbonates (pH = 8), since under these conditions the phenolates undergo complete hydrolysis.

The basic properties of phenol are much less pronounced (by 4-5 orders of magnitude) than those of alcohols. This is due to the fact that the conjugation of the lone electron pair of the oxygen atom with the π-electrons of the benzene ring in the resulting cation is broken:

Acylation. Esterification with carboxylic acids in the presence of H2SO4, which is characteristic of alcohols, is slow in the case of phenol due to the low nucleophilicity of its oxygen center. Therefore, to obtain phenol esters, stronger electrophiles are used - acid chlorides RC0C1 or anhydrides [(RCO) 2 0] of carboxylic acids under anhydrous conditions:

All reactions of phenols considered occur through the O-H bond. Reactions with the cleavage of the C-O bond in phenols, i.e., reactions of substitution of the hydroxyl group in phenol, do not occur in the body.

Redox properties. Phenol easily oxidizes in air, causing its white crystals to quickly turn pink. The composition of the resulting products has not been precisely established.

Phenols have a characteristic color reaction with FeCl3 in aqueous solutions with the appearance of a red-violet color, which disappears after the addition of a strong acid or alcohol. It is assumed that the intense color is associated with the formation of a complex compound containing a phenolate anion in the internal sphere:

In this complex, of all the ligands, the phenolate anion is the most active nucleophile and reducing agent. It is capable of transferring one electron to an electrophile and an oxidizing agent - an iron(3) cation - with the formation in the internal sphere of a radical ion system containing a phenoxyl radical (C6H5O*), which leads to the appearance of intense color:

A similar formation of radicals in the internal sphere of a complex compound due to the internal redox process can also occur in the substrate-enzyme complexes of the body. In this case, the radical particle can either remain bound in the internal sphere or become free when leaving this sphere.

The considered reaction with FeCl3 indicates the ease of oxidation of phenol, especially its anion. Polyhydric phenols are oxidized even more easily. Thus, hydroquinone (especially its dianion) is easily oxidized due to carbon atoms to 1,4-benzoquinone:

Hydroquinone is used in photography because it... reduces AgBr in a photographic emulsion in exposed areas faster than in unexposed areas.

Compounds containing a 1,4-quinoid group are called quinones. Quinones are typical oxidizing agents that form an equilibrium conjugated redox couple with the corresponding hydroquinones (Section 9.1). Such a pair in coenzyme Q is involved in the process of substrate oxidation due to dehydrogenation (Section 9.3.3) and the transfer of electrons along the electron transport chain from the oxidized substrate to oxygen (Section 9.3.4). Vitamins of group K, containing a naphthoquinone group, ensure blood clotting in air.

Electrophilic substitution on the benzene ring. Due to the electron-donating effect of the hydroxyl group, phenol undergoes electrophilic substitution reactions much more easily than benzene. The hydroxyl group orients the attack of the electrophile at the o- and n-positions. For example, phenol decolorizes bromine water at room temperature to form 2,4,6-tribromophenol:

The most important representatives of alcohols and their practical significance. Alkanols are physiologically active substances with narcotic effects. This effect increases with branching and elongation of the carbon chain, passing through a maximum at C6-C8, as well as during the transition from primary to secondary alcohols. The products of the transformation of alcohols in the body can cause their toxic effects.

Methanol CH 3 OH is a strong poison, as it is oxidized in the digestive tract into formaldehyde and formic acid. Already in small doses (10 ml) it can cause blindness.

Ethanol C2H5OH, commonly called simply alcohol. The use of ethanol (alcoholic beverages) initially has a stimulating and then depressive effect on the central nervous system, dulls sensitivity, weakens the function of the brain and muscular system, and worsens reactions. Its prolonged and excessive use leads to alcoholism. The mechanism of action of ethanol on the body is extremely complex and has not yet been fully elucidated. However, an important step in its transformation in the body is the formation of acetaldehyde, which easily reacts with many important metabolites.

Ethylene glycol HOCH2CH2OH is a strong poison, since the products of its transformation in the body are oxalic acid and other equally toxic compounds. It has an alcoholic odor, and therefore can be mistaken for ethanol and cause severe intoxication. It is used in technology as a deicer and for the preparation of antifreeze - liquids with a low freezing point, used to cool engines in winter.

Glycerol HOCH 2 CH(OH)CH 2 OH is a non-toxic, viscous, colorless liquid with a sweet taste. It is part of most saponified lipids: animal and vegetable fats, as well as phospholipids. It is used for the production of glycerol trinitrate, as a softener in the textile and leather industries and as an integral part of cosmetic preparations for skin softening.

Biologically active alcohols are many metabolites belonging to different classes of organic compounds: menthol - terpene class; xylitol, sorbitol, mesoinositol-polyhydric alcohols; cholesterol, estradiol - steroids.

Profile chemical and biological class

Lesson type: lesson of learning new material.

Lesson teaching methods:

• verbal (conversation, explanation, story);
• visual (computer presentation);
• practical (demonstration experiments, laboratory experiments).

Lesson objectives:Learning Objectives: using the example of phenol, to concretize students’ knowledge about the structural features of substances belonging to the class of phenols, to consider the dependence of the mutual influence of atoms in the phenol molecule on its properties; introduce students to the physical and chemical properties of phenol and some of its compounds, study qualitative reactions to phenols; consider the presence in nature, the use of phenol and its compounds, their biological role

Educational goals: Create conditions for students to work independently, strengthen students’ skills in working with text, highlight the main points in the text, and perform tests.

Developmental goals: Create dialogue interaction in the lesson, promote the development of students’ skills to express their opinions, listen to a friend, ask each other questions and complement each other’s speeches.

Equipment: chalk, board, screen, projector, computer, electronic media, textbook “Chemistry”, 10th grade, O.S. Gabrielyan, F.N. Maskaev, textbook “Chemistry: in tests, problems and exercises”, 10th grade, O.S. Gabrielyan, I.G. Ostroumov.

Demonstration: D. 1. Displacement of phenol from sodium phenolate with carbonic acid.

D. 2. Interaction of phenol and benzene with bromine water (video).

D. 3. Reaction of phenol with formaldehyde.

Laboratory experience:1. Solubility of phenol in water at normal and elevated temperatures.

2. Interaction of phenol and ethanol with alkali solution.

3. Reaction of phenol with FeCl 3.

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MUNICIPAL EDUCATIONAL INSTITUTION

"GYMNASIUM No. 5"

TYRNYAUZA KBR

Open lesson-research in chemistry

Chemistry teacher: Gramoteeva S.V.

I qualification category

Class: 10 "A", chemical and biological

Date: 02/14/2012

Phenol: structure, physical and chemical properties of phenol.

Application of phenol.

Profile chemical and biological class

Lesson type: lesson of learning new material.

Lesson teaching methods:

1. verbal (conversation, explanation, story);
2. visual (computer presentation);
3. practical (demonstration experiments, laboratory experiments).

Lesson Objectives: Learning Objectives: using the example of phenol, to concretize students’ knowledge about the structural features of substances belonging to the class of phenols, to consider the dependence of the mutual influence of atoms in the phenol molecule on its properties; introduce students to the physical and chemical properties of phenol and some of its compounds, study qualitative reactions to phenols; consider the presence in nature, the use of phenol and its compounds, their biological role

Educational goals:Create conditions for students to work independently, strengthen students’ skills in working with text, highlight the main points in the text, and perform tests.

Developmental goals:Create dialogue interaction in the lesson, promote the development of students’ skills to express their opinions, listen to a friend, ask each other questions and complement each other’s speeches.

Equipment: chalk, board, screen, projector, computer, electronic media, textbook “Chemistry”, 10th grade, O.S. Gabrielyan, F.N. Maskaev, textbook “Chemistry: in tests, problems and exercises”, 10th grade, O.S. Gabrielyan, I.G. Ostroumov.

Demonstration: D. 1.Displacement of phenol from sodium phenolate with carbonic acid.

D. 2. Interaction of phenol and benzene with bromine water (video).

D. 3. Reaction of phenol with formaldehyde.

Laboratory experience: 1. Solubility of phenol in water at normal and elevated temperatures.

3. Reaction of phenol with FeCl 3 .

PROGRESS OF THE LESSON

1. Organizational moment.
2. Preparing to study new material.

1. Frontal survey:

1. What alcohols are called polyhydric? Give examples.
2. What are the physical properties of polyhydric alcohols?
3. What reactions are typical for polyhydric alcohols?
4. Write qualitative reactions characteristic of polyhydric alcohols.
5. Give examples of the esterification reaction of ethylene glycol and glycerol with organic and inorganic acids. What are the reaction products called?
6. Write the reactions of intramolecular and intermolecular dehydration. Name the reaction products.
7. Write the reactions of polyhydric alcohols with hydrogen halides. Name the reaction products.
8. What are the methods for producing ethylene glycol?
9. What are the methods for producing glycerin?
10. What are the applications of polyhydric alcohols?

1. Checking the house. assignments: page 158, ex. 4-6 (selectively at the board).

1. Learning new material in the form of a conversation.

The slide shows the structural formulas of organic compounds. You need to name these substances and determine which class they belong to.

Phenols - these are substances in which the hydroxo group is connected directly to the benzene ring.

What is the molecular formula of the phenyl radical: C 6 H 5 – phenyl. If one or more hydroxyl groups are added to this radical, we obtain phenols. Note that the hydroxyl groups must be directly attached to the benzene ring, otherwise we will get aromatic alcohols.

Classification

Same as alcohols, phenolsclassified by atomicity, i.e. by the number of hydroxyl groups.

1. Monohydric phenols contain one hydroxyl group in the molecule:

1. Polyhydric phenols contain more than one hydroxyl group in their molecules:

The most important representative of this class is phenol. The name of this substance formed the basis for the name of the entire class - phenols.

Many of you will become doctors in the near future, so they should know as much as possible about phenol. Currently, there are several main areas of use of phenol. One of them is the production of medicines. Most of these drugs are derivatives of phenol-derived salicylic acid: o-HOC 6 H 4 COOH. The most common antipyretic, aspirin, is nothing more than acetylsalicylic acid. The ester of salicylic acid and phenol itself is also well known under the name salol. Para-aminosalicylic acid (PAS for short) is used in the treatment of tuberculosis. And finally, the condensation of phenol with phthalic anhydride produces phenolphthalein, also known as purgen.

Phenols – organic substances whose molecules contain a phenyl radical associated with one or more hydroxy groups.

Why do you think phenols are classified as a separate class, even though they contain the same hydroxyl group as alcohols?

Their properties are very different from those of alcohols. Why?

The atoms in a molecule mutually influence each other. (Butlerov's theory).

Let's look at the properties of phenols using the simplest phenol as an example.

History of discovery

In 1834 German organic chemist Friedlieb Runge discovered a white crystalline substance with a characteristic odor in the products of the distillation of coal tar. He failed to determine the composition of the substance; he did this in 1842. Auguste Laurent. The substance had pronounced acidic properties and was a derivative of benzene, discovered shortly before. Laurent called it benzene phenone, so the new acid was called phenyl acid. Charles Gerard considered the resulting substance to be alcohol and proposed calling it phenol.

Physical properties

Laboratory experience: 1. Study of the physical properties of phenol.

Instruction card

1.Look at the substance given to you and write down its physical properties.

2.Dissolve the substance in cold water.

3. Warm the test tube slightly. Note the observations.

Phenol C6H5 OH (carbolic acid)- colorless crystalline substance, t pl = 43 0 C, t boil = 182 0 C, in air it oxidizes and turns pink, at ordinary temperatures it is limitedly soluble in water, above 66 °C it is miscible with water in any proportions. Phenol is a toxic substance, causes skin burns, is an antiseptic, thereforePhenol must be handled with care!

Phenol itself and its vapors are poisonous. But there are phenols of plant origin, found, for example, in tea. They have a beneficial effect on the human body.

A consequence of the polarity of the O–H bond and the presence of lone pairs of electrons on the oxygen atom is the ability of hydroxy compounds to form hydrogen bonds

This explains why phenol has quite high melting points (+43) and boiling points (+182). The formation of hydrogen bonds with water molecules promotes the solubility of hydroxy compounds in water.

The ability to dissolve in water decreases with increasing hydrocarbon radical and from polyatomic hydroxy compounds to monoatomic ones. Methanol, ethanol, propanol, isopropanol, ethylene glycol and glycerin are mixed with water in any ratio. The solubility of phenol in water is limited.

Isomerism and nomenclature

2 types possible isomerism:

1. isomerism of the position of substituents in the benzene ring;
2. side chain isomerism (structure of the alkyl radical and numberradicals).

Chemical properties

Look carefully at the structural formula of phenol and answer the question: “What is so special about phenol that it was placed in a separate class?”

Those. phenol contains both a hydroxyl group and a benzene ring, which, according to the third position of the theory of A.M. Butlerov, influence each other.

What properties should phenol formally have? That's right, alcohols and benzene.

The chemical properties of phenols are due precisely to the presence of a functional hydroxyl group and a benzene ring in the molecules. Therefore, the chemical properties of phenol can be considered both by analogy with alcohols and by analogy with benzene.

Remember what substances alcohols react with. Let's watch a video of the interaction of phenol with sodium.

1. Reactions involving the hydroxyl group.

1. Interaction with alkali metals(similarity to alcohols).

2C 6 H 5 OH + 2Na → 2C 6 H 5 ONa + H 2 (sodium phenolate)

Do you remember whether alcohols react with alkalis? No, what about phenol? Let's conduct a laboratory experiment.

Laboratory experience: 2. Interaction of phenol and ethanol with alkali solution.

1. Pour a solution of NaOH and 2-3 drops of phenolphthalein into the first test tube, then add 1/3 of the phenol solution.

2. Add NaOH solution and 2-3 drops of phenolphthalein to the second test tube, then add 1/3 part of ethanol.

Make observations and write reaction equations.

1. The hydrogen atom of the hydroxyl group of phenol is acidic in nature. The acidic properties of phenol are more pronounced than those of water and alcohols.Unlike alcohols and water phenol reacts not only with alkali metals, but with alkalis to form phenolates:

C 6 H 5 OH + NaOH → C 6 H 5 ONa + H 2 O

However, the acidic properties of phenols are less pronounced than those of inorganic and carboxylic acids. For example, the acidic properties of phenol are approximately 3000 times less than those of carbonic acid, therefore, by passing carbon dioxide through a solution of sodium phenolate, free phenol can be isolated ( demonstration):

C 6 H 5 ONa + H 2 O + CO 2 → C 6 H 5 OH + NaHCO 3

Adding hydrochloric or sulfuric acid to an aqueous solution of sodium phenolate also leads to the formation of phenol:

C 6 H 5 ONa + HCl → C 6 H 5 OH + NaCl

Phenolates are used as starting materials for the preparation of ethers and esters:

C 6 H 5 ONa + C 2 H 5 Br → C 6 H 5 OC 2 H 5 + NaBr (ethyphenyl ether)

C 6 H 5 ONa + CH 3 COCl → CH 3 – COOC 6 H 5 + NaCl

Acetyl chloride phenylacetate, acetic acid phenyl ester

How can you explain the fact that alcohols do not react with alkali solutions, but phenol does?

Phenols are polar compounds (dipoles). The benzene ring is the negative end of the dipole, the OH group is the positive end. The dipole moment is directed towards the benzene ring.

The benzene ring draws electrons from the lone pair of oxygen electrons. The displacement of the lone pair of electrons of the oxygen atom towards the benzene ring leads to an increase in the polarity of the O-H bond. An increase in the polarity of the O-H bond under the influence of the benzene ring and the appearance of a sufficiently large positive charge on the hydrogen atom leads to the fact that the phenol moleculedissociates in water solutionsacid type:

C 6 H 5 OH ↔ C 6 H 5 O - + H + (phenolate ion)

Phenol is weak acid. This is the main difference between phenols andalcoholswhich arenon-electrolytes.

1. Reactions involving the benzene ring

The benzene ring changed the properties of the hydroxo group!

Is there a reverse effect - have the properties of the benzene ring changed?

Let's do one more experiment.

Demonstration: 2. Interaction of phenol with bromine water (video).

Substitution reactions. Electrophilic substitution reactions in the benzene ring of phenols occur much more easily than in benzene, and under milder conditions, due to the presence of a hydroxyl substituent.

1. Halogenation

Bromination occurs especially easily in aqueous solutions. Unlike benzene, the bromination of phenol does not require the addition of a catalyst (FeBr 3 ). When phenol reacts with bromine water, a white precipitate of 2,4,6-tribromophenol is formed:

1. Nitration also occurs more easily than benzene nitration. The reaction with dilute nitric acid occurs at room temperature. As a result, a mixture of ortho- and para-isomers of nitrophenol is formed:

O-nitrophenol p-nitrophenol

When concentrated nitric acid is used, 2,4,6-trinitrophenol is formed - picric acid, an explosive:

As you can see, phenol reacts with bromine water to form a white precipitate, but benzene does not react. Phenol, like benzene, reacts with nitric acid, but not with one molecule, but with three at once. What explains this?

Having acquired excess electron density, the benzene ring became destabilized. The negative charge is concentrated in the ortho and para positions, so these positions are the most active. The replacement of hydrogen atoms occurs here.

Phenol, like benzene, reacts with sulfuric acid, but with three molecules.

1. Sulfonation

The ratio of ortho- and para-dimensions is determined by the reaction temperature: at room temperature, o-phenolsulfoxylate is mainly formed, at a temperature of 100 0 C – para-isomer.

1. Polycondensation of phenol with aldehydes, in particular with formaldehyde, occurs with the formation of reaction products - phenol-formaldehyde resins and solid polymers ( demonstration):

Reaction polycondensation,i.e., a polymer production reaction that occurs with the release of a low molecular weight product (for example, water, ammonia, etc.),can continue further (until one of the reagents is completely consumed) with the formation of huge macromolecules. The process can be described by the summary equation:

The formation of linear molecules occurs at ordinary temperatures. Carrying out this reaction when heated leads to the fact that the constituents have a branched structure, it is solid and insoluble in water. As a result of heating a linear phenol-formaldehyde resin with an excess of aldehyde, hard plastic masses with unique properties are obtained.

Polymers based on phenol-formaldehyde resins are used for the manufacture of varnishes and paints. Plastic products made on the basis of these resins are resistant to heating, cooling, alkalis and acids, and they also have high electrical properties. The most important parts of electrical appliances, power unit housings and machine parts, and the polymer base of printed circuit boards for radio devices are made from polymers based on phenol-formaldehyde resins.

Adhesives based on phenol-formaldehyde resins are capable of reliably connecting parts of a wide variety of natures, maintaining the highest joint strength over a very wide temperature range. This glue is used to attach the metal base of lighting lamps to a glass bulb.

All plastics containing phenol are dangerous to humans and nature. It is necessary to find a new type of polymer that is safe for nature and easily decomposes into safe waste. This is your future. Create, invent, don’t let dangerous substances destroy nature!”

Qualitative reaction to phenols

In aqueous solutions, monohydric phenols react with FeCl 3 with the formation of complex phenolates, which have a purple color; color disappears after adding strong acid

Laboratory experience: 3. Reaction of phenol with FeCl 3 .

Add 1/3 of the phenol solution to the test tube and drop by drop the FeCl solution 3 .

Record your observations.

Methods of obtaining

1. Cumene method.

Benzene and propylene are used as feedstock, from which isopropylbenzene (cumene) is obtained, which undergoes further transformations.

Cumene method for producing phenol (USSR, Sergeev P.G., Udris R.Yu., Kruzhalov B.D., 1949). Advantages of the method: waste-free technology (yield of useful products > 99%) and cost-effectiveness. Currently, the cumene method is used as the main method in the global production of phenol.

1. Made from coal tar.

Coal tar, containing phenol as one of the components, is treated first with an alkali solution (phenolates are formed) and then with an acid:

C 6 H 5 OH + NaOH → C 6 H 5 ONa + H 2 O (sodium phenolate, intermediate)

C 6 H 5 ONa + H 2 SO 4 → C 6 H 5 OH + NaHSO 4

1. Fusion of salts of arenesulfonic acids with alkali:

300 0 C

C 6 H 5 SO 3 Na + NaOH → C 6 H 5 OH + Na 2 SO 3

1. Interaction of halogen derivatives of aromatic hydrocarbons with alkalis:

300 0 C, P, Cu

C6H5 Cl + NaOH (8-10% solution) → C 6 H 5 OH + NaCl

or with water steam:

450-500 0 C, Al 2 O 3

C 6 H 5 Cl + H 2 O → C 6 H 5 OH + HCl

Biological role of phenol compounds