2-Nitrochlorobenzene
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Names | |
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Preferred IUPAC name
1-Chloro-2-nitrobenzene | |
Other names
2-Chloronitrobenzene
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Identifiers | |
3D model (JSmol)
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ChEBI | |
ChEMBL | |
ChemSpider | |
ECHA InfoCard | 100.001.686 |
EC Number |
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KEGG | |
PubChem CID
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RTECS number |
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UNII | |
UN number | 1578 |
CompTox Dashboard (EPA)
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Properties | |
C6H4ClNO2 | |
Molar mass | 157.55 g·mol−1 |
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) |
Insoluble | |
Solubility in other solvents | Highly soluble in diethyl ether, benzene, and hot ethanol |
Hazards | |
Occupational safety and health (OHS/OSH): | |
Main hazards
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Toxic, Irritant |
GHS labelling: | |
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Danger | |
H301, H302, H311, H312, H317, H331, H332, H350, H351, H361, H372, H411 | |
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 [77 °F], 100 kPa).
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2-Nitrochlorobenzene is an organic compound with the formula ClC6H4NO2. It is one of three isomeric nitrochlorobenzenes.[1] It is a yellow crystalline solid that is important as a precursor to other compounds due to its two functional groups.
Synthesis
[edit]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
[edit]Alkylation and electrophilic aromatic substitution can occur at the chlorinated carbon center, and a diverse array of reactions can be carried out using the nitro group.[1] 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]
- 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
[edit]2-Nitrochlorobenzene is not valuable in itself but is a precursor to other useful compounds. The compound is particularly 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, itself a precursor to many dyes and pesticides.
References
[edit]- ^ a b Gerald Booth, "Nitro Compounds, Aromatic" in Ullmann's Encyclopedia of Industrial Chemistry, Wiley-VCH: Weinheim, 2005. doi:10.1002/14356007.a17_411
- ^ Bogert, Marston T.; Stull, Arthur (1928). "Di-o-Nitrophenyl Disulfide". Organic Syntheses. 8: 64. doi:10.15227/orgsyn.008.0064.