2-Nitroaniline

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2-Nitroaniline
2-nitroaniline chemical structure.png
2-Nitroaniline-3D-balls.png
Names
Preferred IUPAC name
2-Nitroaniline
Systematic IUPAC name
2-Nitrobenzenamine
Other names
ortho-Nitroaniline
o-Nitroaniline
Identifiers
3D model (JSmol)
ChEMBL
ChemSpider
ECHA InfoCard 100.001.687 OOjs UI icon edit-ltr-progressive.svg
EC Number
  • 201-855-4
PubChem CID
RTECS number
  • BY6650000
UNII
UN number 1661
  • InChI=1S/C6H6N2O2/c7-5-3-1-2-4-6(5)8(9)10/h1-4H,7H2 X mark.svgN
    Key: DPJCXCZTLWNFOH-UHFFFAOYSA-N X mark.svgN
  • InChI=1/C6H6N2O2/c7-5-3-1-2-4-6(5)8(9)10/h1-4H,7H2
    Key: DPJCXCZTLWNFOH-UHFFFAOYAV
  • O=[N+]([O-])c1ccccc1N
Properties
C6H6N2O2
Molar mass 138.126 g·mol−1
AppearanceOrange solid
Density 1.442 g/mol
Melting point 71.5 °C (160.7 °F; 344.6 K)
Boiling point 284 °C (543 °F; 557 K)
0.117 g/100 ml (20°C) (SIDS)
Acidity (pKa)-0.3 (of anilinium salt)
-66.47·10−6 cm3/mol
Hazards
GHS labelling:
GHS-pictogram-skull.svg GHS-pictogram-silhouette.svg
Danger
H301, H311, H331, H373, H412
P260, P261, P264, P270, P271, P273, P280, P301+P310, P302+P352, P304+P340, P311, P312, P314, P321, P322, P330, P361, P363, P403+P233, P405, P501
Flash point 168 °C (334 °F; 441 K)
Related compounds
Related compounds
3-Nitroaniline, 4-Nitroaniline
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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2-Nitroaniline is an organic compound with the formula H2NC6H4NO2. It is a derivative of aniline, carrying a nitro functional group in position 2. [1] It is mainly used as a precursor to o-phenylenediamine.

Contents

Synthesis

2-Nitroaniline is prepared commercially by the reaction of 2-nitrochlorobenzene with ammonia: [2]

ClC6H4NO2 + 2 NH3 → H2NC6H4NO2 + NH4Cl

Many other methods exist for the synthesis of this compound. Direct nitration of aniline is inefficient since anilinium is produced instead. Nitration of acetanilide gives only traces of 2-nitro isomer is obtained due to the great steric effect of the amide. Sulfonation is usually used to block the 4 position and increases the effectiveness to 56%. [3] [4]

Laboratory routes to produce 2-nitroaniline 2-nitroaniline synthesis.svg
Laboratory routes to produce 2-nitroaniline

Uses and reactions

2-Nitroaniline is the main precursor to phenylenediamines, which are converted to benzimidazoles, a family of heterocycles that are key components in pharmaceuticals. [2]

Intramolecular hydrogen-bonding results in a very low basicity for 2-nitroaniline. O-Nitroanilin Wasserstoffbrucke.svg
Intramolecular hydrogen-bonding results in a very low basicity for 2-nitroaniline.

Aside from its reduction to phenylenediamine, 2-nitroaniline undergoes other reactions anticipated for aromatic amines. It is protonated to give the anilinium salts. Owing to the influence of the nitro substituent, the amine exhibits a basicity nearly 100,000x lower than aniline itself. Diazotization gives diazonium derivative, [5] which is a precursor to some diazo dyes. Acetylation affords 2-nitroacetanilide.

See also

Related Research Articles

<span class="mw-page-title-main">Ketone</span> Organic compounds of the form >C=O

In organic chemistry, a ketone is an organic compound with the structure R−C(=O)−R', where R and R' can be a variety of carbon-containing substituents. Ketones contain a carbonyl group −C(=O)−. The simplest ketone is acetone, with the formula (CH3)2CO. Many ketones are of great importance in biology and in industry. Examples include many sugars (ketoses), many steroids, and the solvent acetone.

<span class="mw-page-title-main">Aniline</span> Organic compound (C₆H₅NH₂); simplest aromatic amine

Aniline is an organic compound with the formula C6H5NH2. Consisting of a phenyl group attached to an amino group, aniline is the simplest aromatic amine. It is an industrially significant commodity chemical, as well as a versatile starting material for fine chemical synthesis. Its main use is in the manufacture of precursors to polyurethane, dyes, and other industrial chemicals. Like most volatile amines, it has the odor of rotten fish. It ignites readily, burning with a smoky flame characteristic of aromatic compounds. It is toxic to humans.

<span class="mw-page-title-main">Nitration</span> Chemical reaction which adds a nitro (–NO₂) group onto a molecule

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 alcohols and nitric acid. The difference between the resulting molecular structures of nitro compounds and nitrates is that the nitrogen atom in nitro compounds is directly bonded to a non-oxygen atom, whereas in nitrate esters, the nitrogen is bonded to an oxygen atom that in turn usually is bonded to a carbon atom.

<span class="mw-page-title-main">Nitro compound</span> Organic compound containing an −NO₂ group

In organic chemistry, nitro compounds are organic compounds that contain one or more nitro functional groups. The nitro group is one of the most common explosophores used globally. The nitro group is also strongly electron-withdrawing. Because of this property, C−H bonds alpha (adjacent) to the nitro group can be acidic. For similar reasons, the presence of nitro groups in aromatic compounds retards electrophilic aromatic substitution but facilitates nucleophilic aromatic substitution. Nitro groups are rarely found in nature. They are almost invariably produced by nitration reactions starting with nitric acid.

<span class="mw-page-title-main">Azo compound</span> Organic compounds with a diazenyl group (–N=N–)

Azo compounds are organic compounds bearing the functional group diazenyl.

<span class="mw-page-title-main">Aromatic sulfonation</span> Chemical reaction which replaces a hydrogen on an arene with sulfonic acid, –NH–SO3H

In organic chemistry, aromatic sulfonation is an organic reaction in which a hydrogen atom on an arene is replaced by a sulfonic acid functional group in an electrophilic aromatic substitution. Aryl sulfonic acids are used as detergents, dye, and drugs.

<i>o</i>-Phenylenediamine Chemical compound

o-Phenylenediamine (OPD) is an organic compound with the formula C6H4(NH2)2. This aromatic diamine is an important precursor to many heterocyclic compounds. OPD is a white compound although samples appear darker owing to oxidation by air. It is isomeric with m-phenylenediamine and p-phenylenediamine.

Nitrophenols are compounds of the formula HOC6H5−x(NO2)x. The conjugate bases are called nitrophenolates. Nitrophenols are more acidic than phenol itself.

<span class="mw-page-title-main">4-Aminophenol</span> Chemical compound

4-Aminophenol (or para-aminophenol or p-aminophenol) is an organic compound with the formula H2NC6H4OH. Typically available as a white powder, it is commonly used as a developer for black-and-white film, marketed under the name Rodinal.

<span class="mw-page-title-main">3-Nitroaniline</span> Chemical compound

3-Nitroaniline is an organic compound with the formula H2NC6H4NO2. A yellow solid, it is a derivative of aniline, carrying a nitro functional group in position 3. It is an isomer of 2-nitroaniline and 4-nitroaniline. It is used as a precursor to dyes.

The reduction of nitro compounds are chemical reactions of wide interest in organic chemistry. The conversion can be effected by many reagents. The nitro group was one of the first functional groups to be reduced. Alkyl and aryl nitro compounds behave differently. Most useful is the reduction of aryl nitro compounds.

The Béchamp reduction is a chemical reaction that converts aromatic nitro compounds to their corresponding anilines using iron as the reductant:

3-Nitrobenzoic acid is an organic compound with the formula C6H4(NO2)CO2H. It is an aromatic compound and under standard conditions, it is an off-white solid. The two substituents are in a meta position with respect to each other, giving the alternative name of m-nitrobenzoic acid. This compound can be useful as it is a precursor to 3-aminobenzoic acid, which is used to prepare some dyes.

<span class="mw-page-title-main">4-Nitroaniline</span> Chemical compound

4-Nitroaniline, p-nitroaniline or 1-amino-4-nitrobenzene is an organic compound with the formula C6H6N2O2. A yellow solid, it is one of three isomers of nitroaniline. It is an intermediate in the production of dyes, antioxidants, pharmaceuticals, gasoline, gum inhibitors, poultry medicines, and as a corrosion inhibitor.

<span class="mw-page-title-main">2,4,6-Trimethylaniline</span> Chemical compound

2,4,6-Trimethylaniline is an organic compound with formula (CH3)3C6H2NH2. It is an aromatic amine that is of commercial interest as a precursor to dyes. It is prepared by selective nitration of mesitylene, avoiding oxidation of the methyl groups, followed by reduction of the resulting nitro group to the aniline.

1-Naphthol, or α-naphthol, is a organic compound with the formula C10H7OH. It is a fluorescent white solid. 1-Naphthol differs from its isomer 2-naphthol by the location of the hydroxyl group on the naphthalene ring. The naphthols are naphthalene homologues of phenol. Both isomers are soluble in simple organic solvents. They are precursors to a variety of useful compounds.

<span class="mw-page-title-main">4-Nitrochlorobenzene</span> Chemical compound

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 found in rubber. Other isomers with the formula ClC6H4NO2 include 2-nitrochlorobenzene and 3-nitrochlorobenzene.

4-Nitrotoluene or para-nitrotoluene is an organic compound with the formula CH3C6H4NO2. It is a pale yellow solid. It is one of three isomers of nitrotoluene.

<span class="mw-page-title-main">2-Nitrochlorobenzene</span> Chemical compound

2-Nitrochlorobenzene is an organic compound with the formula ClC6H4NO2. 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.

Ortho effect is a organic chemistry phenomenon where the presence of an chemical group at the at ortho position or the 1 and 2 position of a phenyl ring, relative to the carboxylic compound changes the chemical properties of the compound. This is caused by steric effects and bonding interactions along with polar effects caused by the various substituents which are in a given molecule, resulting in changes in its chemical and physical properties. The ortho effect is associated with substituted benzene compounds.

References

  1. "Safety data for o-nitroaniline". Archived from the original on 2009-06-28. Retrieved 2011-01-17.
  2. 1 2 Gerald Booth (2007). "Nitro Compounds, Aromatic". Ullmann's Encyclopedia of Industrial Chemistry . Weinheim: Wiley-VCH. doi:10.1002/14356007.a17_411. ISBN   978-3527306732.
  3. T. W. Grahan, Solomons; Craig, B. Fryhle; Scott, A. Snyder (2011). Organic chemistry (11 ed.). John Wiley & Sons. pp. 606–607. ISBN   978-1119077251.
  4. Louis Ehrenfeld, Milton Puterbaugh (1929). "o-Nitrianiline". Organic Syntheses. 9: 64. doi:10.15227/orgsyn.009.0064.
  5. G. Wittig; R. W. Hoffmann (1967). "1,2,3-Benzothiadiazole 1,1-Dioxide". Org. Synth. 47: 4. doi:10.15227/orgsyn.047.0004.