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2-Nitrochlorobenzene

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2-Nitrochlorobenzene
Names
Preferred IUPAC name 1-Chloro-2-nitrobenzene
Other names 2-Chloronitrobenzene
Identifiers
CAS Number
3D model (JSmol)
ChEBI
ChEMBL
ChemSpider
ECHA InfoCard 100.001.686 Edit this at Wikidata
EC Number
  • 201-854-9
KEGG
PubChem CID
RTECS number
  • CZ0875000
UNII
UN number 1578
CompTox Dashboard (EPA)
InChI
  • InChI=1S/C6H4ClNO2/c7-5-3-1-2-4-6(5)8(9)10/h1-4HKey: BFCFYVKQTRLZHA-UHFFFAOYSA-N
  • InChI=1/C6H4ClNO2/c7-5-3-1-2-4-6(5)8(9)10/h1-4HKey: BFCFYVKQTRLZHA-UHFFFAOYAA
SMILES
  • C1=CC=C(C(=C1)(=O))Cl
Properties
Chemical formula C6H4ClNO2
Molar mass 157.55 g·mol
Appearance Yellow crystals
Density 1.368 g/mL
Melting point 33 °C (91 °F; 306 K)
Boiling point 245.5 °C (473.9 °F; 518.6 K)
Solubility in water Insoluble
Solubility in other solvents Highly soluble in diethyl ether, benzene, and hot ethanol
Hazards
Occupational safety and health (OHS/OSH):
Main hazards Toxic, Irritant
GHS labelling:
Pictograms GHS06: ToxicGHS07: Exclamation markGHS08: Health hazardGHS09: Environmental hazard
Signal word Danger
Hazard statements H301, H302, H311, H312, H317, H331, H332, H350, H351, H361, H372, H411
Precautionary statements P201, P202, P260, P261, P264, P270, P271, P272, P273, P280, P281, P301+P310, P301+P312, P302+P352, P304+P312, P304+P340, P308+P313, P311, P312, P314, P321, P322, P330, P333+P313, P361, P363, P391, P403+P233, P405, P501
Flash point 124 °C (255 °F; 397 K)
Except where otherwise noted, data are given for materials in their standard state (at 25 °C , 100 kPa). Infobox references
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.

Synthesis

Nitrochlorobenzene is typically synthesized by nitration of chlorobenzene in the presence of sulfuric acid:

C6H5Cl + HNO3 → O2NC6H4Cl + H2O

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, 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, it reacts to give di-orthonitrophenyl disulfide:

2 O2NC6H4Cl + Na2S2 → (O2NC6H4S)2 + 2 NaCl

Similarly, it reacts with sodium methoxide to give 2-nitroanisole.

Substitution of chloride by fluoride is also practiced commercially to convert 2-nitrochlorobenzene to 2-fluoronitrobenzene. The Halex process uses potassium fluoride in polar solvents like sulfolane :

O2NC6H4Cl + KF → O2NC6H4F + KCl

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

  1. ^ Booth, Gerald (2000). "Nitro Compounds, Aromatic". Ullmann's Encyclopedia of Industrial Chemistry. Weinheim: Wiley-VCH. doi:10.1002/14356007.a17_411. ISBN 978-3-527-30385-4.
  2. Bogert, Marston T.; Stull, Arthur (1928). "Di-o-Nitrophenyl Disulfide". Organic Syntheses. 8: 64. doi:10.15227/orgsyn.008.0064.
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