Lecture № 9 Heterofunctional carboxylic acids .

1. Lecture № 9 Heterofunctionalcarboxylicacids. Prepared by ass. Medvid I.I., ass. Burmas N.I.

2. Outline • Physical and chemical properties of oxoacids. Acetoacetic ester. • Physical and chemical properties of halogenacids • Physical and chemical properties of hydroxyacids. • Physical and chemical properties of phenolacids. • Physical and chemical properties of aminoacids. • Chloranhydrides of carbonicacid a) Physical and chemical properties of aphosgene 7. Amides of carbonic acid • Physical and chemical properties of an urea • Physical and chemical properties of a guanidine 8. Sulfoacids: • aliphatic sulfoacids • aromatic sulfoacids

3. 9. Aminoacids 1). α-Aminoacids as structure components of proteins. 2). Classification and structure of aminoacids. 3). Chirality of aminoacids. 4). Acid - base properties of aminoacids. 5). Chemical properties of α-aminoacids. 6). Indentification of aminoacids. 7). Proteins. Structureof а protein. 8). Globular and fibrous proteins 9). Simple and conjugated proteins. 10.Peptides: a) acid-base properties; b) optical properties of peptides; c) chemical properties of peptides; d) synthesis of peptides.

4. The most important heterofunctional carboxylic acids are halogenocarboxylic acid (halogenoacid), hydroxycarboxylic acid (hydroxyacid) oxocarboxylic acid (aldehydo- and ketonoacid) and amino- carboxylicacids (aminoacids)

5. 1. Oxoacids To oxoacids include aldehydo- and ketonoacids. These compounds include in the structure of the carboxyl group, aldehyde functional group or ketone functional group. pyroracemic acid, 2-oxopropanoic acid glyoxylic acid, oxoethanoic acid acetoacetic acid, 3-oxobutanoic acid, β-ketobutyric acid γ-ketovaleric acid, 4-oxopentanoic acid, levulinic acid oxalacetic acid, oxobutanedioic acid, ketosuccinic acid

6. Methods of extraction of oxoacids: • Oxidation of hydroxyacids: • Hydrolysis dihalogenocarboxylic acids lactic acid pyroracemic acid 2,2-dichlorpropanoic acid pyroracemic acid (pyruvic acid)

7. Chemical properties of oxoacids • Decarboxylation of α-oxoacids • Decarboxylation of β-oxoacids

8. Acetoacetic ester Acetoacetic ester synthesis is a chemical reaction where ethyl acetoacetate is alkylated at the α-carbon to both carbonyl groups and then converted into a ketone, or more specifically an α-substituted acetone. Acetoacetic ester is a tautomeric substance. He characterized keto-enol tautomery.

9. The enol form of "acetoacetic ester" stand by formation of hydrogen bond:

10. Chemical properties of acetoacetic ester: • Reactions of ketone form:

11. 2. Reactions to enol form: • interaction of “acetoacetic ester” with metallic sodium • interaction of “acetoacetic ester” with NaOH c) interaction “acetoacetic ester” with PCL5 ethyl-3-chlorbutene-2-oate

12. d) interaction of “acetoacetic ester” with bromine water. The discolouration of bromine water, that explained unsaturated of "acetoacetic ester”. e) interaction of “acetoacetic ester” with FeCL3

13. The characteristic feature of “acetoacetic ester” is the ability to ketone decompositionand acid decomposition. Ketone decompositionoccurs when heated in the presence of the dilute solutions of acids or alkalis. Acid decomposition of “acetoacetic ester”

14. An “acetoacetic ester” used in the organic synthesis for the extraction of difference ketones and carboxylic acids.

15. 2. Halogenoacids Halogenoacids are the derivatives of carboxyl acids that contain halogen radical (1 or more). α-bromopropanoic acid 2-bromopropanoic acid 2-bromo-3-methylbutanoic acid, α - bromoisovaleric acid

16. Methods of extraction of halogenocarboxylic acid: • Halogenation of saturated carboxylic acids: • Hydrohalogenation of unsaturated carboxylic acids • Halogenation of aromatic carboxylic acids: acrylic acid β-chloropropanoic acid m-chlorobenzoic acid

17. Physical and chemical properties of halogenocarboxylic acid For physical properties of halogencarboxylic acids are colorless liquids or crystalline substance, soluble in water. Chemical properties: in the molecule of halogenoacids either carboxyl group or halogen radical can react. As the halogen atom separation of carboxyl group inductive effect decreases, and so the acidity decreases. In the transition from mono- to di- and polyhalogencarboxylic acids the acidity increases. The most powerful of carboxylic acid is trifluoroacetic acid – CF3-COOH (pKa 0,23)

18. I. Carboxyl group can react with formation of: • Salts chloroacetat sodium

19. b) complex ethers: c) amides: methyl ether of β-chloropropanoic acid amide β-chloropropanoic acid

20. II. Halogen radical can react with: • ammonium: b) NaOH (water solution): 1) for α-halogenoacids ammonium salt of β-aminopropanoic acid lactic acid

21. 2) for β-halogenoacids 3) for γ,σ-halogenoacids β-chloropropanoic acid β-hydroxypropanoic acid acrylic acid γ-butyrolactone

22. Monochloroacetic acid Trichloroacetic acid Dichloroacetic acid Representatives of halogenocarboxylic acid : These acids are used in organic synthesis Ureide of α-bromisovaleric acid (bromisoval) used in medical practice as a hypnotic.

23. 3. Hydroxyacids Hydroxyacids are the derivatives of carboxyl acids that contain –OH group (1 or more). β α 2-hydroxypropanoic acid α-hydroxypropanoic acid

24. glycolic acid, hydroxyacetic acid, hydroxyethanoic acid tartaric acid α,α’-dihydroxysuccinic acid, 2,3-dihydroxybutandioic acid, lactic acid, α- hydroxypropanoic acid, 2- hydroxypropanoic acid malic acid, hydroxysuccinic acid hydroxybutanedioic acid citric acid, 2-hydroxy-1,2,3-propantricarboxylic acid

25. In a row of hydroxyacids often found the optical isomery. D-, or (R,R)-tartaric acid L-, or (S,S)-tartaric acid mezo-, or (R,S)-tartaric acid

26. Methods of extraction of hydroxyacids: • Hydrolysis of α-halogenoacids • Oxidations of diols and hydroxyaldehydes • Hydration of α,β-unsaturated carboxylic acids lactic acid β-hydroxypropanoic acid

27. 4. Hydrolysis of hydroxynitriles (cyanohydrins)

28. Physical and chemical properties of hydroxycarboxylic acid For physical properties of hydroxycarboxylic acids are colorless liquids or crystalline substance, soluble in water. Chemical properties: in the molecule of hydroxyacids ether –OH group or carboxyl group can react. Carboxyl group can react forming: a) salts: sodium β-hydroxypropanoic acid

29. b) complex ethers: methyl ether of β-hydroxypropanoic acid

30. c) amides: II. –OH group can react with: • hydrohalogens (HCl, HBr, HI, HF) b) can oxidize amide of β-hydroxypropanoic acid β-oxopropanoic acid

31. Related to heat of: 1. α-hydroxyacids lactic acid lactide 2. β-hydroxyacids heating 3-hydroxybutanoic acid butene-2-onic (crotonic) acid

32. heating 3. γ-hydroxyacids 4-hydroxybutanic acid γ-butyrolacton

33. Decomposition of α-hydroxyacids acetic acid formic acid

34. Representatives of hydroxyacids: Milk acid . Milk acid is a trivial name because at first it was extracted from milk. It is present in kefir yogurt, sour milk and other milk products. It can form in muscles during hard and prolonged work. That is why peoples can feel ache in their muscles after physical training. Salts of milk acid are used in medicine. Apple acid . It is present in green apples and some berries. It takes part in biological processes in human organisms and organisms of other alive creatures. In industry it is used for manufacturing of wine, fruit waters and sweets. It is used in medicine for synthesis of some medical preparations. Tartaric acid . It is present in grape. It is used in medicine for synthesis of some medical preparations.

35. Citric acid. It is present in orange, lemon and other citric fruits. It takes part in biological processes in human organism.

36. Phenolacids are the derivatives of aromatic carboxyl acids that contain –OH group (1 or more). 4. Phenolacids. salicylic acid, 2-hydroxybenzoic acid o-hydroxycinnamic acid 4-hydroxybenzoic acid 3,4,5-trihydroxybenzoic acid, gallic acid

37. Methods of phenolacids extraction: • Carboxylation of phenols by carbon oxide (IV): 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: 2. Hydroxylation of arencarboxylic acids

38. 3. Alloying of sulphobenzoic acid with alkalis m-sulphobenzoic acid potassuim salt of 3-hydroxybenzoic acid

39. Chemical properties of phenolacids: Chemical properties of phenolacids due to the presence in their structure of carboxyl group, phenolic hydroxyl and the aromatic nucleus. Decarboxylation

41. O O H O H C C O O N a P O C l , C H O N a N a H C O 3 6 5 3 O C H 6 5 - C O , - H O - N a C l , - N a P O 2 2 3 Phenylsalicylate, salol Sodium salicylate O O H N H C H C O 2 3 C O O H ( C H C O ) O 3 2 C O O H - C H O H 6 5 - C H C O O H 3 Salicylic acid Acetylsalicylic acid, O H aspirin C H O H 3 - H O ( H S O ) 2 2 4 O O O H O H O H C C C O O C H 3 N H N H N H 3 2 Salicylamide Methylsalicylate Oxaphenamide O H

42. 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.

43. 5. Aminoacids • An aminoacid is an organic compound that contains both a amino (–NН2) group and a carboxyl (-СООН) group. The amino acids found in proteins are always α-amino acids.

45. Methods of aminoacids extraction: • Effects of ammonia on halogencarboxylic acids : • Effects of ammonia and HCN on aldehydes α-chlorpropanoic acid α-aminopropanoic acid α-aminopropanonitrile acetalaldehyde aldimine α-aminopropanoic acid

46. 3. Accession of ammoniato the α, β–unsatured acids acrylic acid β-aminopropanoic acid 4. Reduce of nitrobenzoic acid n-nitrobenzoic acid n-aminobenzoic acid

47. Optical properties

48. Physical and chemical properties of aminoacids Both an acidic group (-СООН) and а basic group (-NН2) are present on the same carbon in an α-amino acid. The net result is that in neutral solution, amino acid molecules have the structure: А zwitter-ion is а molecule that has а positive charge on one atom and а negative charge on another atom.

49. Reactions on a amino-group:

50. Reactions to a carboxylic group: