1 / 216

Derivatives of Carboxylic Acids and Nucleophilic Acyl Substitution

Derivatives of Carboxylic Acids and Nucleophilic Acyl Substitution. Carboxylic Acids. A class of organic compounds containing at least one carboxyl group. R = alkyl group or H  alkanoic acid(sat’d) R = aryl group  aromatic carboxylic acid. Aliphatic carboxylic acid

sophia-parsons
Télécharger la présentation

Derivatives of Carboxylic Acids and Nucleophilic Acyl Substitution

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Derivatives of Carboxylic Acids and NucleophilicAcyl Substitution

  2. Carboxylic Acids • A class of organic compounds containing at least one carboxyl group

  3. R = alkyl group or H  alkanoic acid(sat’d) R = aryl group  aromatic carboxylic acid

  4. Aliphatic carboxylic acid = fatty acids (sat’d or unsat’d) ∵ obtained from fat/oil E.g. stearic acid, CH3(CH2)16COOH oleic acid, CH3(CH2)7CH=CH(CH2)7COOH

  5. Carboxylic Acids • Carboxyl group •  combination of the carbonyl group and the hydroxyl group

  6. Nomenclature Suffix : carboxylic acid or oic acid Prefix : carboxy

  7. Q.62 (2Z)-but-2-enoic acid butanoic acid ethanedioic acid

  8. 3-carboxy-3-hydroxypentainedicarboxylic acid Q.62 butanedioic acid 2-hydroxypropane-1,2,3-tricarboxylic acid (citric acid)

  9. Q.62 benzoic acid Benzene-1,3-dicarboxylic acid

  10. Q.62 4-hydroxybenzoic acid phenylethanoic acid

  11. Derivatives of carboxylic acids (pp.9-10)

  12. Acyl (Acid) Chlorides Suffix : -oic acid replaced by –oyl chloride Prefix : chlorocarbonyl

  13. Acyl (Acid) Chlorides 3-chloro-3-oxopropanoic acid Priority : - -COOH > anhydride > ester > acid chloride > acid amide The carbonyl C is counted as part of the carbon skeleton

  14. Q.63 4-chloro-2-methyl-4-oxobutanoic acid hexanedioyl dichloride 3-(chlorocarbonyl)hexanedioic acid

  15. Acid anhydride Suffix : -acid replaced by –anhydride

  16. Acid anhydride * Prefix : n-(alkanoyloxy)-n-oxo(if *C is counted as part of the main chain) n indicates the position of the *C in the main chain

  17. Acid anhydride * Prefix : (alkanoyloxy)carbonyl (if *C is not counted as part of the main chain)

  18. Acid anhydride ethanoic anhydride ethanoic propanoic anhydride

  19. Acid anhydride benzoic ethanoic anhydride butanedioic anhydride

  20. Q.64 Benzene-1,2-dioic anhydride

  21. Ester Suffix : -oic acid replaced by –oate preceded by the name of R’

  22. Ester * Prefix : n-alkoxy-n-oxo(if *C is counted as part of the main chain) n indicates the position of the *C in the main chain

  23. Ester * Prefix : alkoxycarbonyl (if *C is not counted as part of the main chain)

  24. Ester methyl ethanoate ethenyl ethanoate methyl 4-bromobenzoate

  25. Q.65 2-(ethanoyloxy)benzoic acid 2-(acetyloxy)benzoic acid 2-(methoxycarbonyl)benzoic acid

  26. Acid amide Suffix : -oic acid replaced by -amide

  27. Ester * Prefix : n-amino-n-oxo(if *C is counted as part of the main chain) n indicates the position of the *C in the main chain

  28. Ester * Prefix : aminocarbonyl (if *C is not counted as part of the main chain)

  29. Ester N,N-dimethylethanamide (3) ethanamide (1) N-methylethanamide (2)

  30. Q.66 4-amino-4-oxobutanoic acid benzamide 3-(aminocarbonyl)heptanedioic acid

  31. Physical Properties of Alkanoic Acids

  32. Odour Methanoic / ethanoic acid  sharp, irritating odours • Propanoic to heptanoic acid • strong, unpleasant odours • Butanoic acid  body odour Higher members  low volatility  little odour

  33. b.p.  steadily as the number of C atoms  ∵ London dispersion forces become stronger as the size of electron cloud 

  34. HCOOH/CH3COOH have exceptionally high m.p. ∵ smaller size  1. closer packing  2. forming H-bonds more extensitively

  35. Members with EVEN no. of C atoms are more symmetrical  Higher packing efficiency  Higher m.p.

  36. Pure ethanoic acid = glacial ethanoic acid It freezes in cold weather

  37. More extensive H-bonds H-bonds Dipole-dipole interaction Dispersion forces ONLY

  38. Less dense than water except HCOOH/CH3COOH

  39.  as R.M.M.  R.M.M.   extent of H-bond formation   molecules not drawn closer  lower packing efficiency

  40. For alkanes,   as R.M.M.  ∵ no intermolecular H-bonds R.M.M.   Dispersion forces become stronger  closer packing

  41. First FOUR members are miscible with water in all proportions due to extensive H-bond formation between acid molecules and water molecules

  42. From pentanoic acid, solubility  as R.M.M.  The bulky R groups prevent formation of H-bonds between –COOH and H2O

  43. Non-polar ionic Emulsifying action of soap (salts of carboxylic acids) depends on the length of the hydrocarbon chain

  44. Preparation of Carboxylic Acids

  45. 1.Hydrolysis of Nitriles Elimination occurs for 2 and 3 RX as CN is a relatively strong base

  46. Examples

  47. 2.Oxidation of aldehydes and 1alcohols (pp.83-84, 93) 3.Oxidation of aromatic side chains(pp.54-55) 4.Iodoform reactions (p.92)

More Related