By students of Sir Dr. M.S.GOSAVI COLLEGE OF PHARMACEUTICAL EDUCATION AND RESEARCH, NASHIK.

1. Continuous Assessment-1
GROUP NO.06
ROLL NO. 41 TO 48
TOPIC: AROMATIC AMINES
SIR DR. M.S. GOSAVI COLLEGE OF PHARMACEUTICAL EDUCATION AND RESEARCH,
NASHIK

2. Roll no. Names
41. Yash Kahane
42. Prathamesh Kakde
43. Rutuja Kakde
44. Prachi Kangane
45. Shweta Kapile
46. Saniya Kazi
47. Kartik Khairnar
48. Akanksha Khairnar
• Introduction
• Classification
• Properties
• Basicity of Amines
• Effect of Substituent on
Basicity
• Nitrosation reaction
• Coupling reaction
• Sandmayers reaction
• Hinsberg test
• Synthetic uses of aryl
diazonium salts

3.  The nitrogen atom in amine is sp3-hybridised. The three hybrid orbitals in
amines are involved in bond formation whereas one hybrid atomic orbital
contains the lone pair of electrons.
 This results in the development of pyramidal geometry of amines.
 Nitrogen almost has a planar structure in aromatic amines (“anilines”). This is due to the mixture
of the lone pair with the aryl substituent.
Structure:

4. INTRODUCTION:
 These are the derivatives of aromatic hydrocarbon in which a
hydrogen of benzene ring has been replaced by amino group
 All such compound in which an amino or substituted amino group is
bonded directly to an aromatic ring are termed as Aromatic Amines.

5. CLASSIFICATION:
Depending upon the number of alkyl groups directly attached to the amino nitrogen in alkyl
amines can be classified as:
Primary Amines: Those amines in which one alkyl group is directly attached to the nitrogen
atom.
Secondary Amines: Those amines in which two alkyl groups are directly attached to the
nitrogen atom.
Tertiary Amines: Those amines in which three alkyl groups are directly attached to the nitrogen
atom.

6. Aromatic amines in general are :
 colorless liquids or solids
 Having a characteristic odor which is not pleasant
 Turn brown in air owing to oxidation
 Sparingly soluble in water
 Dissolve in benzene and other organic solvents
 They are steam volatile and therefore purified by steam distillation
PROPERTIES:

7. BASICITY OF AMINES: Ammonia is the strong base. Amines are considered to be the alkyl or aryl derivative of
ammonia.

8. Electron releasing group
(-CH3, -OCH3, -NH2)increase the
basicity of aromatic amines.
Electron withdrawing groups (-
NO2, -Br, -COOH) decrease the
basicity of aromatic amines

9.  EFFECT OF SUBSTITUENT ON BASICITY:
1)Effect of ortho substituent
2)Stearic hindrance of substituents
3)H-bonding
Presence of electron-releasing groups on the benzene ring of
aromatic amines enhances the electron density on nitrogen, thus
increase the basicity. On the contrary, presence of electron-
withdrawing reduces the basicity of amines.

11. Nitrosation Reaction:
Nitrous Acid(HNO2) reacts with aromatic amines that provides a test for distinguish between primary,
secondary and tertiary amines.
Nitrous acid is unstable and is prepared in site by reaction of dil.HCL with sodium Nitrate in absence of
heat
NaNO2 + HCL Nacl +D=N-OH(aq)
Primary aromatic amines –
1º amines + cold HNO2+HCL diazonium salt nitrogen is evolved.

12. Secondary Aromatic Amines:
Tertiary Aromatic Amines:

13. COUPLING REACTION:
The term coupling reaction refer to class of organic
reaction that involve the joining of two chemical
species(usually with help of metal catalyst).
 An important type of coupling reaction of organic halide
with an organometilic compound having formula R-M
which facilates the formation of new carbon- carbon bond.
If the organic halide in this reaction has the general formula
R`-X the compound formed as product will have the
formula R-R`.

14. CLASSIFACTION:
 HOMOCOUPLING REACTION:
Here, two identical chemical species are combined to yield
a single product.
Example of homocoupling reaction are :Wurtz reaction ,
Glaser reaction , Pinacol coupling reaction.

15.  HETROCOUPLING REACTION:
Here , the two dissimilar chemical species are joined
together to afford a single product.
Example of hetro coupling reaction are
Grignard reaction, Suzuki reaction.

16. APPLICATION OF COUPLING REACTION:
• Coupling reaction are employed in synthesis of several
pharmaceutical product.
• Many conjugated polymers are prepared via
coupling reactions that involve the use of a metal
catalyst.
• The Suzuki coupling reaction (which is an important
class of coupling reactions) is also used in the
synthetic production of complex compounds. For
example, it is used in the production of caparratriene,
which is highly effective in the treatment of leukaemia.
• Many natural products can be obtained via certain
coupling reactions. For example, benzylisoquinoline
alkaloids can be synthesized with the help of the
Sonogashira cross-coupling reaction.

17. Sandmayer’s Reaction:
 Sandmeyer reaction is a type of substitution reaction that is widely used in the
production of aryl halides from aryl diazonium salts. Copper salts like chloride,
bromide or iodide ions are used as catalysts in this reaction. Notably, Sandmeyer
reaction can be used to perform unique transformations on benzene.
 The transformations include hydroxylation, trifluoromethylation, cyanation, and
halogenation.
 The reaction was first discovered in the year 1884 when Traugott Sandmeyer, a
Swiss chemist, was conducting an experiment to synthesize phenylacetylene from
benzene diazonium chloride and cuprous acetylide. However, at the end of the
experiment, he obtained phenyl chloride as the main product.
 Sandmeyer reaction follows a free radical mechanism. The reaction is actually a
two-step process where the synthesis of aryl halides from primary aryl amines
involves the formation of diazonium salts and the transformation of diazo
intermediates into aryl halides (displacement with a nucleophile). Interestingly, the
nucleophile can be a halide anion, cyanide, water, etc.

18. To elucidate further, the Sandmeyer reaction mechanism commences with a transfer of a single
electron from the copper to the diazonium. This results in the formation of a non-participating
diazo radical as well as copper(II) halide. A molecule of nitrogen gas is then released by the
diazo radical to give aryl radical, which then reacts with the copper(II) halide to restore
the catalyst [copper(I) halide]. After all this, the final product, aryl halide is obtained.

19. Hinsberg Reaction:

20. Hinsberg reagent can be
described as an alternate name
for benzene sulfonyl chloride.

21. Amines serve as nucleophiles in attacking the sulfonyl chloride
electrophile, displacing chloride.
The sulfonamides resulting from primary and secondary amines
are poorly soluble and precipitate as solids from solution:
PhSO₂Cl + 2 RR’NH PhSO₂NRR' + [RR’NH2+]Cl-
For primary amines (R' = H), the initially formed sulfonamide is
deprotonated by base to give water-soluble sulfonamide salt
(Na[PhSO₂NR]):
PhSO2N(H)R + NaOH → Na+[PhSO,NR ] + H2O
Tertiary amines promote hydrolysis of the sulfonyl chloride
functional group, which affords water soluble sulfonate salts.
PhSO₂Cl + R3N + H₂O → R3NH [PhSO3] + HCI

22. Benzene Diazonium Salt
1. It is used in the dye and pigment industries and are
used to produced dye fabrics.
2. In the synthesis of a large variety of organic
compounds. Especially aryl derivatives, because direct
hydrogenation is a not suitable method for aryl halides.
3. Due to their property of breaking down near the UV
light , they are used in document reproduction.
4. They are used as intermediates for introducing -F, -Br, -
Cl, -I, -No2, -OH, -CN group into the aromatic ring.
Because they easily lose Nitrogen reacts with a variety
of nucleophiles.
5. Nitrogen is very stable, and is lost as a gas this provides
a powerful driving force for these reaction to occur.