AMINES NOTES BY SAROHA CLASSES class 12th.pptx

AMINES NOTES BY SAROHA CLASSES class 12th.pptx

1. CLASS-12 TH AMINES BY SAROHA CLASSES

2. Classification of Amines 1° Amines 2° Amines 3° Amines By Replacing 1 H-atom 2 H-atom 3 H-atom

3. Examples of Amines Ethylmethylamine Aniline Diphenylamine

4. P r e p aration of Amines

5. Reduction of Nitro Compounds Preparation of Amines Nitrobenzene Aniline Nitrobenzene Aniline

6. Hoffmann Ammonolysis of Alkyl Halides Preparation of Amines RX RX RX NH 3 Ammonia RX R-NH 2 1° Amine R 2 NH 2° Amine R 3 N 3° Amine + - R 4 N X 4° Ammonium salt Mixture is obtained ❖ 1 o amine is obtained as a major product by taking large excess of ammonia.

7. Reduction of Nitriles Preparation of Amines 3 2 CH -C ≡ N CH CH -NH 2 2 5 Na/C H OH 3 Acetonitrile H 2 /Ni Or LiAlH 4 Ethylamine Red with Na/C 2 H 5 OH is called Mendius Reduction

8. Reduction of Amides Preparation of Amines Amide Amine

9. Preparation of Amines “To prepare 1° Alkyl Amines” Gabriel Phthalimide Synthesis

10. Hoffmann Bromamide Degradation Preparation of Amines Amide 1° Amine Sodium Carbonate Sodium Bromide “To prepare 1° Amines”

11. Chemical Reactions of Amines

12. Chemical Reactions Basic Character of Amines

13. Stronger Base Basic Character of Amines In Terms of K b & pK b values Larger K b value Smaller pK b value

14. Order of Basic Strength BASIC STRENGTH +I Effect ∝ In Gaseous Phase

15. Order of Basic Strength In Aqueous Medium BASICITY Depends on +I Effect Solvation Effect Stearic Hindrance

16. Order of Basic Strength In Aqueous Medium ∴ Experimentally determined order of basicity is : R ⇒ CH 3 R ⇒ C 2 H 5 : 2° > 1° > 3° > NH 3 : 2° > 3° > 1° > NH 3

17. Order of Basic Strength “Aromatic Amine are less basic than Aliphatic Amine” “ ∵ Due to Resonance Lone Pair is not easily available for protonation”

18. Acylation Chemical Reactions Ethanamine N-Ethylethanamide N-Ethylethanamine N,N-Diethylethanamide “Given by 1° & 2° Amines”

19. Chemical Reactions Carbylamine Reaction R-NH 2 + R-NC + 3KCl + 3H 2 O 1° Amine Δ CHCl 3 + Chloroform Isocyanide (Foul smell) 3KOH Potassium hydroxide Potassium chloride “Given by 1 o Aliphatic & Aromatic Amines”

20. Chemical Reactions HNO 2 Nitrous Acid Reaction with Nitrous acid RNH 2 R 2 N-N=O + H 2 O N-Nitroso dialkylamine R-OH + H 2 O + N 2 Alcohol R 2 NH R 3 N R + - 3 NH NO 2 Trialkyl ammonium nitrite Yellow oil “For Aliphatic Amines”

21. Chemical Reactions Reaction with Nitrous acid “For 1° Aromatic Amines” NaCl Aniline Benzenediazonium chloride HNO 2 + Nitrous acid NaNO 2 + HCl Sodium nitrite HNO 2 + HCl 273-278 K Diazotization Reaction

22. Chemical Reactions Phenol Aniline ꞵ -naphthol Orange Dye Yellow Dye Red Dye Coupling Reactions of Diazonium chloride with

23. Chemical Reactions Coupling Reaction “With Phenol”

24. Chemical Reactions Coupling Reaction “With Aniline”

25. Chemical Reactions Coupling Reaction “With ꞵ -naphthol”

26. Hinsbe r g ’ s Test for Amines

27. Hinsberg’s Test for Amines To distinguish 1°, 2° & 3° Amines Benzene Sulphonyl chloride R 1 ° R-NH2 2 ° R2-NH 3 ° R3-N Soluble in NaOH N-Alkyl benzene sulphonamide R R N,N-Dialkyl benzene sulphonamide Insoluble in NaOH

28. E l e ct r o p hilic S ubstitution Rxn. of Aniline

29. Electrophilic Substitution Rxn. Aniline 2,4,6-Tribromoaniline Acetanilide p-Bromoacetanilide Major p-Bromoaniline Major Bromination

30. Electrophilic Substitution Rxn. Nitration 51% 47 % 2 % Meta directing ∴ 47% meta product

31. Electrophilic Substitution Rxn. Aniline Acetanilide p-Nitroacetanilide Major p-Nitroaniline Major “ To form para product” Nitration

32. Electrophilic Substitution Rxn. Sulphonation Anilium hydrogensulphate Sulphanilic acid Zwitter ion

33. Electrophilic Substitution Rxn. Friedel Crafts Rxn “Due to salt formation N becomes highly deactivating”