| IUPAC name
| Other names
ortho-Dichlorobenzene, o-Dichlorobenzene, odcb, o-Dichlorobenzol
|3D model (Jmol)|| Interactive image|
|Molar mass||147.01 g/mol|
|Melting point||−17.03 °C (1.35 °F; 256.12 K)|
|Boiling point||180.5 °C (356.9 °F; 453.6 K)|
|Vapor pressure||1 mmHg (20° C)|
|Safety data sheet||External MSDS|
|Ingestion hazard||Toxic if swallowed|
|Inhalation hazard||Causes respiratory tract irritation|
|Eye hazard||Causes eye irritation|
|Skin hazard||Causes skin irritation|
|Flash point||66 °C (151 °F; 339 K)|
|Lethal dose or concentration (LD, LC):|
LD50 (median dose)
| 500 mg/kg (oral, rat, rabbit)|
2000 mg/kg (oral, guinea pig)
4386 mg/kg (oral, mouse)
LCLo (lowest published)
| 1000 ppm (guinea pig, 20 hr)|
800 ppm (guinea pig, 24 hr)
821 ppm (rat, 7 hr)
|US health exposure limits (NIOSH):|
|C 50 ppm (300 mg/m3)|
|C 50 ppm (300 mg/m3)|
IDLH (Immediate danger)
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
|(what is ?)|
1,2-Dichlorobenzene, or orthodichlorobenzene (ODCB), is an organic compound with the formula C6H4Cl2. This colourless liquid is poorly soluble in water but miscible with most organic solvents. It is a derivative of benzene, consisting of two adjacent chlorine centers.
Production and uses
1,2-Dichlorobenzene is obtained as a side-product of the production of chlorobenzene:
5Cl + Cl
2 → C
2 + HCl
The reaction also affords the 1,4- and small amounts of the 1,3-isomer. The 1,4- isomer is preferred over the 1,2- isomer due to steric hindrance. The 1,3- isomer is uncommon because it is a meta- compound, while chlorine, like all halogens, is a ortho/para- directors in terms of electrophilic aromatic substitution.
It is mainly used as a precursor to 1,2-dichloro-4-nitrobenzene, an intermediate in the synthesis of agrochemicals. In terms of niche applications, 1,2-dichlorobenzene is a versatile, high-boiling solvent. It is a preferred solvent for dissolving and working with fullerenes. It is an insecticide for termites and locust borers, historically used by the United States Forest Service to combat widespread bark beetle outbreaks.
Data from human exposure to 1,2-dichlorobenzene shows that concentrations of 100 ppm have been reported to cause sporadic irritation of the eyes and respiratory tract. The Occupational Safety and Health Administration and the National Institute for Occupational Safety and Health have set occupational exposure limits at a ceiling of 50 ppm, over an eight-hour workday.
- Merck Index, 11th Edition, 3044
- "NIOSH Pocket Guide to Chemical Hazards #0189". National Institute for Occupational Safety and Health (NIOSH).
- "o-Dichlorobenzene". National Institute for Occupational Safety and Health (NIOSH). 4 December 2014. Retrieved 6 March 2015.
- Gerald Booth (2007). "Nitro Compounds, Aromatic" in Ullmann's Encyclopedia of Industrial Chemistry Wiley-VCH, Weinheim, 2005.
- Technical Order 2J-1-13
- CDC - Documentation for Immediately Dangerous To Life or Health Concentrations (IDLHs)
- CDC - NIOSH Pocket Guide to Chemical Hazards