4-Chloro-1-nitrobenzene; 4-Chloronitrobenzene; p-Nitrochlorobenzene; PNCBO
|Molar mass||157.55 g·mol−1|
|Appearance||Light yellow solid|
|Density||1.52 g/cm³ (20 °C)|
|Melting point||83.6 °C (182.5 °F; 356.8 K)|
|Boiling point||242.0 °C (467.6 °F; 515.1 K)|
|Solubility in other solvents||Soluble in toluene, ether, acetone, hot ethanol|
|Vapor pressure||0.2 mmHg (30°C)|
|Safety data sheet||External MSDS|
|Flash point||12 °C (54 °F; 285 K)|
|Lethal dose or concentration (LD, LC):|
LD50 (Median dose)
|812 mg/kg (rat, oral)
1414 mg/kg (mouse, oral)
440 mg/kg (mouse, oral)
420 mg/kg (rat, oral)
LC50 (Median concentration)
|164 mg/m3 (cat, 7 hr)|
|US health exposure limits (NIOSH):|
|TWA 1 mg/m3 [skin]|
IDLH (Immediate danger
|Ca [100 mg/m3]|
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
|what is: / ?)(|
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 common antioxidants found in rubber. Other isomers with the formula ClC6H4NO2 include 2-nitrochlorobenzene and 3-nitrochlorobenzene.
This reaction affords both the 2- and the 4-nitro derivatives, in about a 1:2 ratio. These isomers are separated by distillation. 4-Nitrochlorobenzene was originally prepared by the nitration of 4-bromochlorobenzene by Holleman and coworkers.
4-Nitrochlorobenzene is an intermediate in the preparation of a variety of derivatives. Nitration gives 2,4-dinitrochlorobenzene, and 3,4-dichloronitrobenzene. Reduction with iron metal gives 4-chloroaniline. The electron-withdrawing nature of the appended nitro-group makes the benzene ring especially susceptible to nucleophilic aromatic substitution, unlike related chlorobenzene. Thus, the strong nucleophiles hydroxide, methoxide, and amide displace chloride to give respectively 4-nitrophenol, 4-nitroanisole, 4-nitroaniline. 
Another major use of 4-nitrochlorobenzene is its condensation with aniline to produce 4-nitrodiphenylamine. Reductive alkylation of the nitro group affords secondary aryl amines, which are useful antioxidants for rubber.
The National Institute for Occupational Safety and Health considers 4-nitrochlorobenzene as a potential occupational carcinogen that may be absorbed through the skin. The Occupational Safety and Health Administration set a permissible exposure limit of 1 mg/m3, while the American Conference of Governmental Industrial Hygienists recommends an airborne exposure limit of 0.64 mg/m3, over a time-weighted average of eight hours.
- "NIOSH Pocket Guide to Chemical Hazards #0452". National Institute for Occupational Safety and Health (NIOSH).
- Gerald Booth "Nitro Compounds, Aromatic" in Ullmann's Encyclopedia of Industrial Chemistry, Wiley-VCH: Weinheim, 2005. doi:10.1002/14356007.a17_411
- "The nitration of mixed dihalogen benzenes" Recueil des Travaux Chimiques des Pays-Bas et de la Belgique. Amsterdam, 1915; pp. 204-235.
- CDC - Immediately Dangerous to Life or Health Concentrations (IDLH): p-nitrochlorobenzene
- CDC - NIOSH Pocket Guide to Chemical Hazards
- New Jersey Department of Health and Senior Services - Hazardous Substance Fact Sheet