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METHODS FOR OBTAINING PRIMARY AROMATIC
AMINES, NITRO COMPOUNDS, PROPERTIES OF AMINO COMPOUNDS
Kungiratov Inom Nazarullayevich
Master's student at Termez State University
Mamatqoriyev Otabek Vahobjonovich
Master's student at Termez State University
Abstract.
We all know that amines are widely used in industry and technology.
Many of them are used as organic bases in chemical reactions, as medicines, solvents,
and pesticides. Some amines are used as solvents in the extraction of uranium ore,
others are used to combat agricultural pests. In this article, we will consider their
industrial production and many of their properties.
Key words.
Amino group, amines, nitro compounds, amino compounds,
nitrosamine, nitrobenzene,
Аннотация
. Мы все знаем, что амины широко используются в
промышленности и технике. Многие из них используются как органические
основания в химических реакциях, как лекарства, растворители и пестициды.
Некоторые амины используются как растворители при добыче урановой руды,
другие — для борьбы с сельскохозяйственными вредителями. В этой статье мы
рассмотрим их промышленное производство и многие их свойства.
Ключевые
слова.
Аминогруппа,
амины,
нитросоединения,
аминосоединения, нитрозамин, нитробензол,
INTRODUCTION
We know that nitro compounds are compounds in which the C-atom in the
molecule is directly bonded to the nitro group –NO
2
. The lower homologues of nitro
compounds are colorless, odorless liquids, insoluble in water, soluble in ether and
alcohol. As the number of carbons increases, their solubility and density in water
decrease, and their boiling point increases. They do not conduct electricity. Nitro
compounds are flammable, their vapors are toxic. Nitro compounds are liquids with a
pleasant odor, poorly soluble in water. Toxic, flammable without decomposition. The
density of nitro compounds with up to four carbons in their structure is less than one.
The chemical properties of nitro groups arise due to the presence of a nitro group
in the molecule. One of the most important properties of nitro compounds is their
conversion into amino compounds when reduced:
R –NO
2
+ 6[H]
R –NH
2
+ 2H
2
O
CH
3
–CH
2
–NO
2
+ 6[H] CH
3
–CH
2
–NH
2
+ 2H
2
O
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This reaction shows that nitrogen in nitro compounds is directly
combined with carbon. When isomers of nitro compounds, that is, nitrite esters, are
reduced, an alcohol and hydroxylamine or ammonia are formed.
CH
3
–O –N = O + 2H
2
CH
3
–OH + NH
2
OH
LITERATURE ANALYSIS AND METHODOLOGY
Primary aromatic amines R–NH
2
can be prepared by many methods. The main
methods for their preparation are:
a. From nitroaromatic compounds
b. From aromatic halogens
c. From aromatic aldehydes or ketones
d. Aminolysis
e. Reductive amination
In the process of nitroaromatic synthesis, primary aromatic amines are obtained
by reducing aromatic nitro compounds. This process is usually carried out using
reducing agents such as iron (Fe), tin (Sn), or hydrogen (H₂).
C₆H₅NO₂ + 3H₂ → C₆H₅NH₂ + 2H₂O
When derived from aromatic halogens, they react with ammonia (NH₃) or
compounds with ammonia ligands to form primary amines.
C₆H₅Cl + NH₃ → C₆H₅NH₂ + HCl
Aromatic aldehydes or ketones react with ammonia or amines to form arylamines.
This process can also lead to the formation of primary amines.
Amines can be formed by the reaction of aromatic halogen compounds with
amines. This process is called aminolysis.
In the reductive amination method, amines are obtained by reacting aromatic
carboxylic acids with ammonia or ammonium salts.
RESULTS.
Amino compounds can be obtained by reacting alcohols and alkyl
halides with ammonia, reducing nitro compounds, nitriles and isonitriles, and oxidizing
acid amides. In industry, when alcohols are treated with ammonia at high temperatures
(t=300°C) in the presence of a catalyst (Al
2
O
3
, ThO
2
), a mixture of primary, secondary
and tertiary amines is formed.
German chemist A.B. Hoffmann was able to obtain primary, secondary, tertiary
amines and quaternary ammonium bases by reacting alkyl halides with ammonia
according to the following scheme. Therefore, this reaction is called the Hoffmann
reaction. To carry out this reaction, an alcoholic solution of ammonia is heated with
alkyl halides (R – X). Let us consider this reaction using the example of the reaction of
methyl chloride with ammonia. When methyl chloride is treated with ammonia, methyl
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ammonium chloride is formed. The resulting methyl ammonium chloride
reacts with a molar amount of ammonia to form a primary amine:
R –Cl + NH
3
[R –NH
3
]
+
Cl
-
R –NH
2
+ NH
4
Cl
Step 1:
CH
3
Cl + NH
3
[CH
3
NH
3
]
+
Cl
-
+ NH
3
CH
3
NH
2
+ NH
4
Cl
Step 2: Methylamine combines again with methyl chloride to form
dimethylammonium chloride:
CH
3
–NH
2
+ CH
3
Cl
[(CH
3
)
2
NH
2
]
+
Cl
-
The resulting dimethylammonium chloride reacts with a molar amount of
ammonia to form free dimethylamine:
[(CH
3
)
2
NH
2
]
+
Cl
-
NH
4
Cl + CH
3
–NH –CH
3
Step 3: Dimethylamine reacts with methyl chloride to form trimethylammonium
chloride:
CH
3
–NH–CH
3
+CH
3
Cl [(CH
3
)
3
NH]
+
Cl
-
The resulting trimethylammonium chloride reacts with a molar amount of
ammonia to form free trimethylamine.
Step 4. The trimethylamine molecule adds another molecule of methyl chloride to
form tetramethylammonium chloride.
The resulting quaternary ammonium salt does not decompose under the influence
of ammonia. Since the amines in the mixture formed as a result of the reaction have
different boiling points, they are separated from each other by fractionation and
distillation.
Amines are formed when nitro compounds, nitriles, oximes and hydrazones are
reduced with hydrogen atoms in the presence of a Ni catalyst. The process can be
carried out in neutral, weakly acidic and alkaline environments.
CONCLUSION
Primary aromatic amines are obtained by many chemical methods, mainly by
reduction of nitroaromatic compounds. Nitro compounds are known for their electronic
properties and chemical reactivity. As a result, these products are used in industry and
in many sectors.
LIST OF REFERENCES
1. О. Я. Нейланд Органическая химия. М.: «Школа Вишши». 1990. Б.563-
582.
2. Yoqubovich M. S., Amonovich T. M. regional focus and tautomericity in the
series of aroylhydrasones of β-dicarbonyl compounds //Journal of Pharmaceutical
Negative Results. – 2022. – С. 279-287.
SYNAPSES:
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3. Дж. Робертс, М. Казерио. Основная органическая химия. М.:
«Мир». 1978. ТС 565-575.
4. S. Masharipov, L.Tirkashev ,”Kimyo” Toshkent – 2007 y 245-252 b.
5. Юнусов Р.Ю.Органик кимё. Т.: Ўзбекистон, 1995. -328 б.
6. Степаненко Б. Н. Органик химия Т.Ўқитувчи, 1995.-370 б.
7. Юсупов Д., Туробжонов С.М., Кодиров Х.Э., Икромов А., Каримов А.У.
Органик кимёнинг бошлангич асослари. Тошкент, 2006. -290 б.
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