2-Nitrochlorobenzene is an
organic compound
Some chemical authorities define an organic compound as a chemical compound that contains a carbon–hydrogen or carbon–carbon bond; others consider an organic compound to be any chemical compound that contains carbon. For example, carbon-co ...
with the formula ClC
6H
4NO
2. It is one of three isomeric
nitrochlorobenzenes.
It is a yellow crystalline solid that is important as a precursor to other compounds due to its two functional groups.
Synthesis
Nitrochlorobenzene is typically synthesized by
nitration
In organic chemistry, nitration is a general class of chemical processes for the introduction of a nitro group () into an organic compound. The term also is applied incorrectly to the different process of forming nitrate esters () between Alcohol ...
of
chlorobenzene
Chlorobenzene (abbreviated PhCl) is an aryl chloride and the simplest of the chlorobenzenes, consisting of a benzene ring substituted with one chlorine atom. Its chemical formula is C6H5Cl. This colorless, flammable liquid is a common solvent a ...
in the presence of
sulfuric acid
Sulfuric acid (American spelling and the preferred IUPAC name) or sulphuric acid (English in the Commonwealth of Nations, Commonwealth spelling), known in antiquity as oil of vitriol, is a mineral acid composed of the elements sulfur, oxygen, ...
:
:C
6H
5Cl + HNO
3 → O
2NC
6H
4Cl + H
2O
This reaction affords a mixture of isomers. Using an acid ratio of 30% nitric acid, 56% sulfuric acid and 14% water, the product mix is typically 34-36% 2-nitrochlorobenzene and 63-65%
4-nitrochlorobenzene
4-Nitrochlorobenzene is the organic compound with the formula ClC6H4NO2. It is a pale yellow solid. 4-Nitrochlorobenzene is a common intermediate in the production of a number of industrially useful compounds, including antioxidants commonly fou ...
, with only about 1%
3-nitrochlorobenzene.
[
]
Reactions
2-Nitrochlorobenzene can be reduced to the 2-chloroaniline with Fe/HCl mixture, the Bechamp reduction.[
2-Nitrochlorobenzene, like its isomers, is reactive toward nucleophiles, resulting in chloride substitution. With ]polysulfide
Polysulfides are a class of chemical compounds derived from anionic chains of sulfur atoms. There are two main classes of polysulfides: inorganic and organic. The inorganic polysulfides have the general formula . These anions are the conjugate bas ...
, it reacts to give di-orthonitrophenyl disulfide:sodium methoxide
Sodium methoxide is the simplest sodium alkoxide. With the formula , it is a white solid, which is formed by the deprotonation of methanol. It is a widely used reagent in industry and the laboratory. It is also a dangerously caustic base.
...
to give 2-nitroanisole.
Substitution of chloride by fluoride is also practiced commercially to convert 2-nitrochlorobenzene to 2-fluoronitrobenzene. The Halex process
In chemistry, the Halex process is used to convert aromatic chlorides to the corresponding aromatic fluorides. The process entails ''Hal''ide ''ex''change, hence the name. The reaction conditions call for hot (150-250 °C) solution of the ary ...
uses potassium fluoride
Potassium fluoride is the chemical compound with the formula KF. After hydrogen fluoride, KF is the primary source of the fluoride ion for applications in manufacturing and in chemistry. It is an alkali halide salt and occurs naturally as the ...
in polar solvents like sulfolane
Sulfolane (also tetramethylene sulfone, IUPAC nomenclature, systematic name: 1λ6-thiolane-1,1-dione) is an organosulfur compound, formally a cyclic sulfone, with the formula . It is a colorless liquid commonly used in the chemical industry as a s ...
:
:
Applications
2-Nitrochlorobenzene is useful because both of its reactive sites can be utilized to create further compounds that are mutually ''ortho''. Its derivative 2-chloroaniline is a precursor to 3,3’-dichlorobenzidine, a precursor to dyes and pesticides.
References
{{DEFAULTSORT:Nitrochlorobenzene, 2-
Nitrobenzene derivatives
2-Chlorophenyl compounds