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1.Introduction & History :1.1 Introduction to aniline :Structure:-
 Aniline is an organic compound with
chemical formula of C6H7N or C6H5NH2.
 Aniline has 6 Carbon atoms , 7 Hydrogen
atoms & 1 Nitrogen atom.
 Aniline is made up of two groups :1. Phenyl group
2. Amino group
 As per above figure the phenyl group (boxed
in blue) is attached to the amino group
(boxed in red).
 Aniline has a Phenyl group, so we can say
that it is an aromatic & it also contain Amino
group, so it also means it is an Amine.
 Aniline is a prototypical Aromatic Amine.
 Aniline is a flammable liquid chemical having
pungent unpleasant odour and is slightly
soluble in water.
 It can be colourless to brown, and it is oily in
nature
1.2 History of Aniline : Aniline was first separated in 1826 by Otto
Unverdorben by destructive distillation of
Indigo and called it crystalline.
 In 1834, Friedlieb Runge separated Aniline
from Coal tar.
 When it is treated with chloride of Lime it
gives beautiful blue colour & named it
‘Kyanol'
 In 1840 Carl Julius Fritzsche (1808-1871)
treated Indigo with caustic potash &
obtained an oil and named it Aniline.
 In 1842 Nikolai Nikolaevid Zinin converted
Nitro Aromatics like Nitrobenzene to amines
by reduction with Sodium Sulfides &
obtained Aniline.
ARNO2 + 3H2S -------》 ARNH2 + 3S + 2H2O
 In 1843, August Wilhelm Von Hofmann
showed that all these substance are same,
known there after as Phenyl Amine or
Aniline.
 In 1856, Sir William Henry Perkin, a student
at Royal college of chemistry in London,
partially transformed Aniline into a crude
mixture which when extracted with Alcohol,
produced a substance with an intense purple
colour.
 Perkin further carried out trials with his
friend and his brother and satisfied
themselves that they might be able to scale
up production of the purple substance and
commercialise it as a dye which they called
Mauveine.
 This process was to become one of the first
commercial process to generate o synthetic
organic chemical.
 During the last three decades, polyurethane
plastics have emerged as a growth industry
and aniline once again plays a key role as an
industrial intermediate used in the
manufacture of MDI, 4,4’-diphenylmethane
diisocyanate, a key commercial monomer in
the manufacture of polyurethane plastics.
2.properties of Aniline :2.1 Physical Properties :PROPERTY
VALUE
Molecular formula
C6H7N
Molecular weight
Boiling point, 0C (@101.3 K pa)
93.129
184.4
Critical temperature
425.6*c
Odour
Aromatic. Amine like
Physical state and appearance
Oily liquid
Freezing point
-6.03*c
Taste
Burning
Refractive Index
1.5863
Viscosity mpa.s(=cp)
-
20*c
4.35
60*c
1.62
Enthalpy of dissociation, kj/mol
21.7
Heat of combustion, kj/mol
3394
Ionisation potential, Ev
7.70
Dielectric constant, at 25*c
6.89
Specific heat , at 25*c, j/(g.k)
2.06
Heat of vaporisation, j/g
478.5
Flash point (close cup)
70
2.2 Chemical Properties : Amines are bases because the lone pair of
electrons on the nitrogen atom can accent
a hydrogen ion –in other words, for exactly
the same reason ammonia is a base.
2.2.1 The reaction of aniline with acids:  Aniline reacts with acids like hydrochloric
acid in exactly the same way as any other
amine. Despite the fact that the aniline is
only a very weak base, with a strong acid
like HCL the reaction is completely
straightforward.
 Aniline is only very slightly soluble in water
but dissolved freely in dilute HCL. A solution
of salt is formed aniline chloride salt.
2.1.3. Reaction of aniline with Halogen (CL, I,
BR, F) group:  The presence of the amino group activates
the ortho and para positions of the
aromatic ring and, as a result, aniline reacts
readily with bromine or chlorine. Under
mild conditions, bromination yields 2,4,6Tribromo aniline.
2.1.3.1 Recovery of aniline from aniline salt
 To get the aniline back from phenyl
ammonium ion present in the salt, all you
have to do is to take the hydrogen ion away
again. You can do that by adding any strong
base.
 Normally you would choose sodium
hydroxide solution.
2.1.4 Condensation:  Depending on the reaction conditions, a
variety of condensation products are
obtained from the reaction of aromatic
amines with aldehydes, ketones, acetyls,
and orthoformate.
 Primary aromatic amines react with
aldehydes to form Schiff bases. Schiff bases
formed from the reaction of lower aliphatic
aldehydes, such as formaldehyde and
acetaldehyde, with primary aromatic
amines are often unstable and polymerize
readily. Aniline reacts with formaldehyde in
aqueous acid solutions to yield mixtures of
a crystalline timer of the Schiff base,
methylenedianilines, and polymers.
2.1.5 Oxidation:  Aniline was selectively converted into the
corresponding
nitroso
benzene
and
nitrobenzene by oxidation with 30% aqueous
hydrogen peroxide. The reaction was catalysed
by various heteropolyoxometalates, at room
temperature, in dichloromethane under twophase conditions. Findings show that
H3PW12O40 is the best catalyst in the
oxidation of aniline.
3. Use of Aniline: The largest application of aniline is for the
preparation of methylene dianiline and
related compounds by condensation with
formaldehyde.
 As additives to rubber, aniline derivatives
suchas phenylenediamines and diphenyla
mine, are antioxidants.
 Illustrative of the drugs prepared from
aniline is paracetamol.
 The principal use of aniline in the dye
industry is as a precursor to indigo, the
blue of blue jeans.[6]
 Some early American rockets, such as
the Aerobee and WAC Corporal, used
aniline with furfuryl alcohol as a fuel
with nitric acid
 Anilines are used in the rubber industry for
the processing of rubber chemicals and
products such as car tyres, balloons,
gloves, etc.
 It is used as a dyeing agent in the
manufacture of clothes such as jeans, etc
 It is employed in the production of drugs
such
as
paracetamol,
Tylenol,
acetaminophen.
 It is used as a pesticide and fungicides in
the agricultural industry
 It is used for the manufacture of its some
derivatives such as acetamide, sulphanilic
acid and sulpha drugs, etc.
 It is used as an accelerator in vulcanizing
rubber.
 Aniline, a primary aromatic amine, is a
weak base and forms salts with mineral
acids
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