2-Nitrochlorobenzene
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.
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| Names | |
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| Preferred IUPAC name 1-Chloro-2-nitrobenzene | |
| Other names 2-Chloronitrobenzene | |
| Identifiers | |
| 3D model (JSmol) | |
| ChEBI | |
| ChEMBL | |
| ChemSpider | |
| ECHA InfoCard | 100.001.686 | 
| EC Number | 
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| KEGG | |
| PubChem CID | |
| 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 | 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). Infobox references | |
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 30/56/14, the product mix is typically 34-36% 2-nitrochlorobenzene and 63-65% 4-nitrochlorobenzene, with only about 1% 3-nitrochlorobenzene.
Reactions
    
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. Treatment of 2-nitrochlorobenzene with sodium methoxide gives 2-nitroanisole.
Applications
    
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
    
- Gerald Booth, "Nitro Compounds, Aromatic" in Ullmann's Encyclopedia of Industrial Chemistry, Wiley-VCH: Weinheim, 2005. doi:10.1002/14356007.a17_411