Under normal conditions, phosgene is a gas that condenses into a liquid at a temp. bale and densitya
Phosgene is highly toxic. It has a strong effect on the respiratory organs and mucous membranes. In the First World War, it was used as a pungent suffocating odor.
Under the action of water (or preferably aqueous alkali) it decomposes with the formation of hydrochloric acid and carbon dioxide:
Phosgene is obtained from chlorine and carbon monoxide in the presence of a catalyst specially treated to increase its porosity:
Phosgene serves as a starting material for the synthesis of various organic compounds.
carbon disulfide Of the derivatives of carbonic acid containing sulfur, carbon disulfide is widely used. It is a colorless mobile liquid with a temp. bale having an ethereal odor (technical carbon disulfide, has an unpleasant odor reminiscent of the smell of radish). Carbon disulfide is poisonous and extremely flammable, as its vapors ignite at low temperatures.
Carbon disulphide is used as an initial product for the synthesis of carbon tetrachloride (p. 74), in the production of viscose fiber (p. 345), as well as a solvent for fats, etc.
Carbon disulfide is obtained by passing sulfur vapor over. hot coal:
At present, the most cost-effective way to obtain carbon disulfide is the interaction of methane with sulfur vapor over silica gel:
Carbamide (urea) is a complete amide, carbonic acid:
This is one of the first organic substances obtained synthetically from inorganic substances (Wohler, 1828).
Carbamide is a crystalline substance with a temp. sq. 133 °C, easily soluble in water and alcohol. Forms salts with one equivalent of acids, for example:
When heated solutions of carbamide in the presence of acids or alkalis, it is easily hydrolyzed with the formation of carbon dioxide and ammonia:
When nitrous acid acts on carbamide, carbon dioxide, nitrogen and water are formed:
When carbamide is heated with alcohols, urethanes are obtained - esters of carbamic acid.
Urethanes are crystalline substances that are soluble in water.
When carbamide interacts with formaldehyde in a neutral or slightly alkaline medium at a temperature of about 30 ° C, monomethylolcarbamide and dimethylolcarbamide are formed:
These derivatives, when heated in an acidic medium, form urea polymers - the basis of common plastics - amino plastics (p. 331) and adhesives for gluing wood.
Carbamide (urea) plays an important role in metabolism in animal organisms; is the end product of nitrogen metabolism, in which nitrogenous substances (for example, proteins), having undergone a number of complex transformations in the body, are excreted in the urine in the form of urea (hence its name).
Carbamide is a concentrated nitrogen fertilizer (contains 46% nitrogen) and is quickly absorbed by plants. In addition, carbamide is successfully used for feeding livestock.
Currently, urea is used to isolate paraffinic hydrocarbons of normal structure from petroleum products. The fact is that carbamide crystals form "crystalline pores", so narrow that hydrocarbons of a normal structure penetrate into them, but hydrocarbons with a branched chain cannot penetrate. Therefore, urea crystals adsorb only hydrocarbons of normal structure from the mixture, which, after the dissolution of carbamide, are separated from the aqueous layer.
In industry, carbamide is obtained from ammonia and carbon dioxide at 185 ° C and pressure
thiocarbamide crystalline substance; pace, sq. 172°C. Easily soluble in water, hardly soluble in alcohol. Thiocarbamide can be obtained by the action of hydrogen sulfide on cyanamide
or by heating ammonium thiocyanate. It is used to obtain carbamide polymers.
Carbon dioxide (carbon dioxide)-participant in many carboxylation and decarboxylation reactions in vivo And in vitro.
Carboxylation is possible when compounds with a partial negative charge on the carbon atom react with carbon dioxide. In the body, the interaction of carbon dioxide with acetyl coenzyme A leads to the formation of malonyl coenzyme A.
Like carbonic acid itself, some of its derivatives are also unknown in free form: ClCOOH monochloride and monoamide - carbamic acid H 2 NCOOH. However, their esters are quite stable compounds.
For the synthesis of carbonic acid derivatives, one can use phosgene(dichloranhydride) COCl 2, easily formed by the interaction of carbon monoxide with chlorine in the light. Phosgene is an extremely poisonous gas (bp. 8 o C), in the First World War it was used as a chemical warfare agent.
Ethyl ester of chloroformic acid, when reacted with ammonia, forms ethyl ester of carbamic acid H 2 NCOOC 2 H 5 . Esters of carbamic acid (carbamates) have a common name - urethanes.
Urethanes have found application in medicine as medicines, in particular meprotan And ethacizin.
Urea (urea)(NH 2) 2 C=O is the most important nitrogen-containing end product of human metabolism (about 20-30 g/day of urea is excreted in the urine).
Acids and alkalis, when heated, cause the hydrolysis of urea; in the body, it is hydrolyzed by the action of enzymes.
When slowly heated to a temperature of 150-160 ° C, urea decomposes with the release of ammonia and the formation biuret.
When biuret interacts in alkaline solutions with copper(II) ions, a characteristic violet coloration is observed due to the formation of a chelate complex (biuret reaction). The biuret residue in the chelate complex has an imide structure.
Derivatives of carboxylic acids containing a urea residue as a substituent are ureides. They are used in medicine, in particular α-bromoisovaleric acid ureide - bromized
(bromural) - used as a mild sleeping pill. Its effect is due to a combination of bromine and isovaleric acid residue known for its inhibitory effect on the central nervous system.
Guanidine (iminourea)- a nitrogenous derivative of urea - is a strong base, since the conjugate acid - guanidinium ion - is mesomerically stabilized.
The guanidine residue is part of the α-amino acid - arginine and the nucleic base - guanine.
3.2 Heterofunctional compounds in life processes
general characteristics
Most substances involved in metabolism are heterofunctional compounds.
Compounds are called heterofunctional, in the molecules of which there are different functional groups.
Combinations of functional groups characteristic of biologically important compounds are presented in Table 3.2.
Table 3.1. The most common combinations of functional groups in biologically important aliphatic compounds
Among the heterofunctional compounds in natural objects, the most common are amino alcohols, amino acids, hydroxycarbonyl compounds, as well as hydroxy and oxo acids (Table 9.2).
Table 9.2. Some hydroxy and oxo acids and their derivatives
* For di- and tricarboxylic acids - with the participation of all carboxyl groups. For incomplete salts and functional derivatives, a prefix is added hydro)-, e.g. "hydroxalate" for the anion HOOC-COO - .
Of particular biological importance α-amino acids are covered in chapter 12. Polyhydroxy aldehydes and polyhydroxy ketones (carbohydrates) are covered in chapter 13.
In the aromatic series, important natural biologically active compounds and synthetic drugs (see 9.3) are based on i-aminophenol, i-aminobenzoic, salicylic And sulfanilic acid.
The systematic names of heterofunctional compounds are built according to the general rules of substitutional nomenclature (see 1.2.1). However, for a number of widely used acids, trivial names are preferred (see Table 9.2). Their Latin names serve as the basis for the names of anions and acid derivatives, which often do not coincide with Russian trivial names.
Reactivity
Carbonic acid chloride - phosgene:
Like all acid chlorides, phosgene has a high acylating ability:
Amides of carbonic acid
1) Carbamic acid
Carbamic acid- semi-amide (acid amide) of carbonic acid - unstable:
2) Urea
Urea– carbamide, diamide of carbonic acid:
Urea is the most important end product of protein metabolism in mammals. An adult excretes 20-30 g of urea in the urine per day.
Wöhler Synthesis (1828).
Industrial method for obtaining urea
Urea is a large-tonnage product of the chemical industry (world production is more than 100 million tons per year). It is widely used as a nitrogen fertilizer and for the production of urea-formaldehyde resins. In the chemical and pharmaceutical industry, it is used to produce barbiturates.
Chemical properties of urea
1) Basicity:
2) Decomposition when heated:
3) Decomposition by nitrous acid
Urea can be quantified by the amount of nitrogen released.
(Van Sleik method).
3) Guanidine
Guanidine has an unusually high basicity comparable to that of inorganic alkalis. This is due to the high degree of structural symmetry of its protonated form and the maximum delocalization of the (+) charge:
Guanidine residues are found in some natural compounds and medicinal substances, for example:
Sulfur in the composition of organic compounds has a different degree of oxidation.
Thiols and thioethers
When replacing a halogen with an SH group, thiols are formed:
Thiols have a higher acidity than alcohols:
Thiolate anions are strong nucleophiles; when interacting with halogen derivatives, they form thioesters:
The sulfur atom in thioethers is the center of basicity and nucleophilicity; when interacting with halogen derivatives, thioethers form trialkylthionium salts:
Thiols under mild conditions are easily oxidized, forming disulfides:
The direction of the reaction changes when
OB potential of the medium: with a high OB potential - to the right, with a low OB potential - to the left. Thiol-disulfide interconversions play an important role in the formation of the structure and regulation of the functions of natural proteins.
Sulfoxides and sulfones
During the oxidation of thioethers, the sulfur atom adds oxygen, and sulfoxides and sulfones are sequentially formed:
Dimethyl sulfoxide (DMSO, dimexide) is a colorless liquid with a boiling point. 189 ° C, soluble in water and in organic solvents. It is widely used in organic synthesis as a polar aprotic solvent.
Due to its ability to quickly diffuse through the skin, carrying substances dissolved in it, it is used in pharmacy as a component of medicinal ointments.
Sulfonic acids (sulfonic acids)
Sulfonic acids (or sulfonic acids) are compounds that contain sulfo group:
Methods for obtaining sulfonic acids
1) Aliphatic sulfonic acids
2) Aromatic sulfonic acids are obtained by sulfonation of benzene and its derivatives (see "Chemical properties of arenes")
Chemical properties of sulfonic acids
Sulfo group -
1) strong electron acceptor;
2) she has high acidity(comparable to sulfuric acid);
3) when nucleophilic attack on the neighboring C-atom can be replaced for other leftovers.
4) High polarity and ability to hydrate - the reason solubility sulfonic acids in water.
1) Acidity
In an aqueous medium, sulfonic acids are almost completely ionized:
With alkalis, they form water-soluble salts:
2) Replacement of the sulfo group with other residues
3) Formation of derivatives by the sulfo group
PROGRAM
course in organic chemistry
for students of the Faculty of Biology and Soil
INTRODUCTION
The subject of organic chemistry. The history of the emergence of organic chemistry and the reasons for its separation into a separate science. Distinctive features of organic compounds and organic reactions.
The structure of organic compounds. Theory of chemical structure. The role of A.M. Butlerov in its creation. Chemical bonds: simple and multiple. Structural formula. Isomerism. Homology. Dependence of chemical properties on the composition and structure of the substance. chemical function. main functional groups.
Classification of organic compounds. Principles of systematic (IUPAC) nomenclature.
Chemical bond in the molecules of organic compounds. Types of chemical bond. Ionic, covalent, coordination bonds. Semipolar connection. The role of the electronic octet. Electronic configurations of elements. Atomic orbitals and valence states of carbon. Hybridization of atomic orbitals: sp3,sp2, sp(three valence states of a carbon atom). s- and p-bonds. The main parameters of a covalent bond are: bond energy, bond length, bond polarity and polarizability. The electronegativity of the elements. The concept of mesomerism (resonance). Electronic substituent effects: inductive ( I), mesomeric ( M).
Isomerism of organic compounds. Structural isomers and stereoisomers. Fundamentals of stereochemistry. Spatial structure of methane and its homologues. The principle of free rotation and the limits of its applicability. Shielded and hindered conformations. Conformations of open chain compounds. Conformational formulas of Newman and "goat" type. Conformation of the cyclohexane ring. Axial and equatorial connections. Inversion of the chair conformation. Comparison of stability of cyclohexane derivatives with axial and equatorial positions of substituents. 1,3-Diaxial interaction.
Geometric ( cis - trans) isomerism and the conditions for its appearance in the series of olefins, cycloalkanes. E-, Z- nomenclature.
Optical isomerism. Optical activity and optically active substances. Molecular asymmetry as a condition for the appearance of optical activity. Asymmetric carbon atom. Enantiomers and diastereomers. R- And S- nomenclature to designate the configuration of the center of chirality. Fisher projection formulas. D- and L-nomenclature. Stereoisomerism of compounds with several centers of chirality. Erythro- and threoisomers. Mesoforms. racemic modification.
Classification of organic reactions according to the nature of the transformations and the nature of the reagents.
HYDROCARBONS
Alkanes. Homologous series of methane. Isomerism. Nomenclature. Ways to get. Physical properties, their dependence on chain length and structure. Chemical properties. Radical substitution reactions (S R): halogenation (influence of the nature of the halogen), nitration (Konovalov), sulfochlorination, oxidation. Initiation and inhibition of radical reactions. Reactivity of hydrogen atoms associated with primary, secondary and tertiary carbon atoms. Alkyl radicals and their relative stability.
Alkenes. Isomerism. Nomenclature. Ways to get. physical properties. Length and energy of double bond formation. Chemical properties. Electrophilic addition reactions: halogens, hydrogen halides, water, hypohalic acids, sulfuric acid. The mechanism of electrophilic addition reactions. Stereo- and regional orientation of accession. Carbocations, their stability depending on the structure. Markovnikov's rule and its modern justification. Radical addition: addition of HBr in the presence of peroxides. Nucleophilic addition. Polymerization: cationic, anionic and radical. catalytic hydrogenation. Oxidation: epoxidation according to Prilezhaev, oxidation with potassium permanganate, ozonation. Chemical properties of the a-methylene link adjacent to the p-bond (allylic position): chlorination, oxidation.
Alkynes. Isomerism. Nomenclature. Syntheses of acetylene and its homologues. Characterization of physical properties. Chemical properties of acetylenes: addition reactions, substitution reactions involving a mobile hydrogen atom at carbon with a triple bond. Acetylides. Polymerization of acetylene to benzene, vinylacetylene, cyclooctatetraene.
Alkadienes. Types of alkadienes. Isomerism. Nomenclature. Stereochemistry of allenes. Molecular asymmetry. Conjugated - 1,3-dienes. Methods for obtaining dienes. physical properties. Lengths of carbon-carbon bonds in 1,3-butadiene and its energy of formation. Manifestation of the effect of conjugation. 1,2- and 1,4-addition to 1,3-dienes - electrophilic addition of halogens and hydrogen halides. Carbocations of the allyl type. Cycloaddition to a diene system: Diels-Alder diene synthesis. Polymerization of 1,3-dienes. Synthetic rubber based on 1,3-butadiene (divinyl). Copolymers of divinyl with styrene, acrylonitrile, butyl rubber. Natural rubber: its structure, ozonolysis, processing into rubber.
Cycloalkanes. Classification. Isomerism. Nomenclature. General and special methods for the synthesis of small, medium and large cycles. Physical and chemical properties. Comparative evaluation of the reactivity and thermal stability of cyclopropane, cyclobutane, cyclopentane and cyclohexane. Bayer's stress theory and its modern understanding. Estimation of intensity of cycles on the basis of heats of combustion. Modern understanding of the structure of cyclopropane. Conformations of cycloalkanes. Cycloalkenes and cycloalkadienes.
aromatic hydrocarbons. Features of the chemical properties of benzene and its homologues. The structure of benzene (valence angles, interatomic distances). Energy of formation and heat of hydrogenation of benzene. stabilization energy. Aromatic character of the benzene nucleus. Modern conception of the nature of aromaticity. Non-benzenoid aromatic compounds. Hückel's aromaticity rule. Aromaticity of heterocyclic compounds: furan, thiophene, pyrrole, pyridine. Aromaticity of cyclopropenyl cation, cyclopentadienyl anion, cycloheptatrienyl cation. Lack of aromatic properties in cyclooctatetraene.
Benzene homologues. Homologous series of benzene. Isomerism in the series of alkylbenzenes. Nomenclature. Laboratory methods of synthesis. Production methods in industry. Reactions of electrophilic substitution in the aromatic nucleus. General patterns and mechanism of these reactions. electrophilic reagents. Halogenation, nitration, sulfonation, alkylation, acylation. Influence of electron-donating and electron-withdrawing substituents (activating and deactivating) on the direction and rate of electrophilic substitution in the benzene nucleus. Influence of inductive and mesomeric effects of substituents. Substitution Orientation Rules: ortho- And pair- orientants (substituents of the first kind) and meta- orientants (substituents of the second kind). Coordinated and non-coordinated orientation. Halogenation and oxidation of side chains.
Polynuclear aromatic hydrocarbons.
a) Hydrocarbons with non-condensed nuclei. Diphenyl. diphenylmethane and triphenylmethane. Triphenylmethyl radical, cation and anion. Reasons for their stability.
b) Hydrocarbons with condensed nuclei. Naphthalene and anthracene. Sources of receipt. Isomerism of monosubstituted derivatives. The structure of naphthalene and anthracene. Addition and substitution reactions. Hydrogenation, oxidation, halogenation, nitration, sulfonation. Comparative evaluation of the aromatic character of benzene, naphthalene and anthracene. Phenantrene. Distribution of the phenanthrene skeleton in natural compounds.
HYDROCARBON DERIVATIVES
Halogen derivatives.
a) Alkyl halides. Isomerism. Nomenclature. Production methods: direct halogenation of alkanes, addition of hydrogen halides to alkenes and alkynes, from alcohols by the action of halogen derivatives of phosphorus. Physical and chemical properties. Reactions of nucleophilic substitution of halogen. Mechanisms of S N 1 and S N 2, stereochemistry of reactions. Nucleophile. Leaving group. Formation, stabilization and rearrangement of carbonium ions. Dependence of the reaction mechanism on the structure of the halogen derivative and on the nature of the solvent. Comparison of S N 1 and S N 2 reactions. Reactions of elimination of hydrogen halides (E1 and E2): stereochemistry, direction of elimination. Zaitsev's rule. Competition between substitution and elimination reactions depending on the nature of the reagent and reaction conditions. Reactions of alkyl halides with metals. Grignard reagents: preparation and properties.
b) Aromatic halogen derivatives (Aryl halides). Nomenclature. Preparation: direct halogenation to the core, from diazonium salts. Chemical properties. Reactions of electrophilic substitution (influence of halogens). Reactions of nucleophilic substitution in halogenaryls.
ALCOHOL
Monohydric saturated alcohols. Isomerism. Nomenclature. Obtaining: from alkyl halides, hydration of alkenes, reduction of carbonyl compounds. Obtaining primary, secondary and tertiary alcohols using Grignard reagents (synthesis planning and limitations). physical properties. Association. Hydrogen bond. Chemical properties of alcohols. Acid-base properties of alcohols. Reactions involving the О-Н bond: the action of metals and organometallic compounds, the formation of esters of mineral acids, the esterification reaction. Reactions involving the C-OH bond and their mechanism: substitution of hydroxyl for halogen. Dehydration of alcohols - intramolecular and intermolecular. Reaction mechanism, Zaitsev-Wagner rule. Dehydrogenation and oxidation of alcohols.
Dihydric alcohols (glycols). Classification, isomerism. Nomenclature. Methods for obtaining glycols. Features of physical and chemical properties. dehydration of glycols. Pinacol rearrangement. Oxidation reactions.
polyhydric alcohols. Glycerol. Synthesis. Chemical properties and applications. Nitroglycerine. Polyhydric alcohols: erythritols, pentites, hexites.
PHENOLS
Monohydric phenols. Isomerism, nomenclature. Industrial production methods: alkaline smelting of sulfonates, hydrolysis of aryl halides, cumene oxidation. Preparation from diazonium salts. Chemical properties. Acidity of phenols. Reactions involving the O-H bond: the formation of phenolates, ethers and esters. Williamson reaction. Mutual influence of hydroxyl groups and the aromatic nucleus of phenol. Electrophilic substitution reactions: halogenation, sulfonation, nitration, combination with diazo compounds. Condensation of phenol with formaldehyde. Oxidation and reduction of phenols.
polyhydric phenols. Pyrocatechin, resorcinol, hydroquinone.
ETHERS
Classification. Isomerism. Nomenclature. Receiving methods. Physical and chemical properties. Formation of oxonium compounds. Substitution of the alkoxy group in ethers (cleavage of ethers).
Cyclic ethers. Epoxy. Receipt. Chemical properties of epoxides. Ring opening reactions catalyzed by acids and bases (reaction mechanism, stereochemistry, direction of ring opening), reaction with organometallic compounds. Tetrahydrofuran. Dioxane.
Amines. Primary, secondary and tertiary amines. Amines, aliphatic and aromatic. Isomerism and nomenclature. Methods for the synthesis of amines. Physical and chemical properties of amines. Basic character of amines. Influence of the nature and number of alkyl or aryl groups in an amine on its basicity. Alkylation of amines. Quaternary ammonium bases and their salts. Acylation of amines. Properties and applications of acyl derivatives. Reactions of electrophilic substitution in a number of aromatic amines: halogenation, nitration, sulfonation. Amides of sulfanilic acid (sulfanilamide preparations). The action of nitrous acid on primary, secondary and tertiary amines of the aliphatic and aromatic series.
Aromatic diazo compounds. diazotization reaction. Conditions for carrying out and reaction mechanism. Diazonium cation: stability and electrophilic character. Reactions of diazo compounds with nitrogen evolution: substitution by halogen, hydroxyl, cyano group, hydrogen and other atoms and groups. Reactions of diazo compounds without nitrogen evolution. Azo coupling reaction as an electrophilic substitution reaction. flow conditions. Azo dyes - oxyazo- and aminoazo compounds. Indicator properties of azo dyes on the example of methyl orange. Relationship between color and texture. Recovery of diazo compounds.
Amino alcohols. Ethanolamine (colamine). Choline. Acetylcholine. Sphingosine.
CARBONYL COMPOUNDS
Limit aldehydes and ketones(derivatives of alkanes, cycloalkanes and aromatic hydrocarbons). The structure of the carbonyl group. Isomerism. Nomenclature. Industrial production of formaldehyde from methyl alcohol, acetaldehyde from acetylene. General methods for the preparation of aldehydes and ketones. Chemical properties. Comparison of the reactivity of aldehydes and ketones (aliphatic and aromatic). Nucleophilic addition at the carbonyl group: water, alcohols, hydrocyanic acid, sodium bisulfite, organomagnesium compounds. General scheme of reactions with ammonia derivatives. Reactions with amines, hydroxylamine, hydrazines, semicarbazide. Acid and basic catalysis of addition reactions. Recovery of carbonyl compounds to alcohols, hydrocarbons. Oxidation of aldehydes and ketones. Disproportionation reactions (Cannizzaro, Tishchenko). Reactions involving hydrogen a-carbon atom. Halogenation. haloform reaction. Aldol seal. The mechanism of the reaction and the role of the catalyst. Croton condensation.
Unsaturated carbonyl compounds. a-,b-Unsaturated aldehydes and ketones. Receipt. Conjugation of a carbonyl group and a double bond. Addition reactions of electrophilic and nucleophilic reagents. polymerization. Acrolein. Crotonaldehyde.
carboxylic acids
monocarboxylic acids. Isomerism Nomenclature. Synthesis methods. physical properties. The structure of the carboxyl group. acid properties. acidity constant. Influence of the effect of substituents on the strength of carboxylic acids. Reactions that take place with a break in the O-H bond. Salts of carboxylic acids. Reactions that take place with a break in the C-OH bond: the formation of functional derivatives of carboxylic acids. Esterification reaction and its mechanism. Equilibrium constant. Preparation of acid halides, anhydrides and amides. The mechanism of the nucleophilic substitution reaction in acids and their derivatives. Comparison of the reactivity of acid derivatives in reactions with nucleophilic reagents. Acid halides. Chemical properties. Interaction with water, ammonia, amines, alcohols. Acylation reactions. Amides. Reduced basicity of amides. Hydrolysis of amides in acidic and alkaline media. Dehydration. Amide bond in protein molecules. Complex ethers. Chemical properties. Hydrolysis of esters and its mechanism. transesterification reaction. Interaction with the Grignard reagent. Recovery of esters. Nitriles. Hydrolysis and reduction to amines. Reactions of acids involving hydrogen at a-carbon atom: halogenation, oxidation. Decarboxylation of carboxylic acids.
Unsaturated monocarboxylic acids. Isomerism. Nomenclature. Mutual influence of double bond and carboxyl group. Addition of electrophilic and nucleophilic reagents. Higher unsaturated fatty acids: oleic, linoleic acid. Esters of higher fatty acids and glycerol are fats. Vegetable oils and their types. The structure of natural glycerides and their properties. Configuration of natural triacylglycerols containing an asymmetric carbon atom. hydrolysis of fats. Soap. Hydrogenation of fats. Lipids. Glycolipids. Glycerophospholipids. Ethanolamine phosphoglycerides (cephalins). Cholinephosphoglycerides (lecithins).
dicarboxylic acids. Isomerism. Nomenclature. Synthesis methods. Physical and chemical properties. Dissociation steps and acidity constants. Formation of two series of functional derivatives. Relation to heating oxalic, malonic, succinic, glutaric and phthalic acids. cyclic anhydrides. Phthalimide, potassium phthalimide. Malonic ether. Substitution reactions involving hydrogen atoms of the methylene group. Synthesis of mono- and dibasic acids using malonic ester. Adipic acid. Polycondensation reactions and their use in industry (artificial fiber).
DERIVATIVES OF CARBONIC ACID
Phosgene. Synthesis, properties and application. Esters of chlorocarbonic and carbonic acids. Carbamic acid: carbamates, esters (urethanes). Urea. Synthesis methods. Structure and reactions. Biuret. Acylation of urea (ureides).
OXYACIDS
Classification. dihydric monobasic acids. Isomerism. Nomenclature. Glycolic acid. Lactic acids and their stereoisomerism. Methods for the synthesis of a-, b- and g-hydroxy acids. Chemical properties. Dehydration of hydroxy acids. lactides and lactones. Dibasic triatomic hydroxy acids. malic acids. Stereoisomerism. The phenomenon of the Waldenian conversion.
Dibasic tetrahydric hydroxy acids. Tartaric acids, their stereoisomerism. Grape and mesotartaric acids. Stereochemistry of compounds with two asymmetric atoms, identical and different. Racemates. Diastereomers. Mesoforms. aromatic hydroxy acids. Salicylic acid. Receipt and application. Aspirin.
OXO ACIDS (ALDEHYDO AND KETO ACIDS)
Classification. Nomenclature. Glyoxylic and pyruvic acids. Getting and properties. Decarboxylation and decarbonylation. b-Keto acids: acetoacetic acid and its ester. Synthesis of acetoacetic ester. Ester Claisen condensation, its mechanism. Chemical properties of acetoacetic ester. Reactions characteristic of the ketone and enol forms of acetoacetic ester. The phenomenon of tautomerism. Keto-enol tautomerism of acetoacetic ester. Reasons for the relative stability of the enol form. Acid and ketone cleavage of acetoacetic ester. Synthesis of ketones, mono- and dicarboxylic acids.
Similar information.
.Iolnal acid
in a free state
does not exist, decomposes into u.u.o. as a dibasic acid
However, it can form a number of functional derivatives: partial and complete acid halides, esters, amides, etc.
CHLOROAN HYDRIDES
carbonic acid monochloride, chlorocarbonic acid
carbonic acid dichloride, phosgene
Phosgene is a complete carbonic acid chloride!, translated means born of light. Obtained by mixing gases of carbon (II) oxide and chlorine. The reaction occurs only when irradiated with UV light:
co + C12 - g \u003d o
Phosgene is a suffocating gas with a "kip" odor of fresh hay. Its vapors are heavier than air and irritate the lungs, causing edema.
Chemical properties. 1. Interaction with H20. As an acid chloride, it is easily decomposed by water to form carbonic and hydrochloric acids.
2. interaction with a*p*piaki*p
h. interaction with alcohols
CARBONIC ACID AMIDES
non-full amide of carbonic acid is called caryamipic
acid:
kkarbammic acid is unstable and does not occur in the free state, as it easily decomposes at room temperature:
carbamic acid derivatives are also easily decomposed.
Heating ammonium carbamate leads to its decomposition to urea and HO:
carbamic acid esters! called urethanes. General
urethane formula:
carboxylic acids
they are obtained from phosgene and the corresponding alcohol, followed by the action of ammonia:
or from diethyl ether of carbonic acid! - reaction with ammonia:
Urethanes - substances with clear melting points
and serve to identify alcohols. They are used as sleeping pills.
Urea - diamide of carbonic acid:
Urea is the end product of protein breakdown. She
is of great biochemical importance.
Urea was first obtained by Wehler in 1828 from the ammonium salt of cyanic acid:
In industry, urea is obtained from and 1h!!.,:
Urea is a colorless crystalline substance, highly soluble in water, of a neutral nature.
Chemical properties. 1. Interaction of urea with acids. urea protonation occurs at the oxygen atom, since the basicity of the -1CHN groups is significantly reduced
as a result of pairing:
26. Derivatives of carbonic acid
2. hydrolysis of mucin. urea when heated easily hydro-
lysed with water or aqueous solutions of acids and alkalis.
3. Interaction with nitrous acid. when interacting
with nitrous acid, urea decomposes with the release of nitrogen, carbon (IV) oxide and water:
4. ratio of urea to heat. When urea is heated, biuret is formed:
Iuret is highly soluble in water.
Further heating leads to the formation of cyanuric
carboxylic acids
cyanuric acid is insoluble in water, with a solution of ^u^o^
in the presence of 1ChH3, it forms a complex compound colored lilac.
5. Urea reacts with acylating reagents to form acylureas. 1H-Acyl derivatives of urea are called ureides.
urea and its derivatives are widely used in the synthesis
medicines.
