1,2-Dichlorobenzene, or orthodichlorobenzene (ODCB), is an

organic compound In chemistry, organic compounds are generally any chemical compounds that contain carbon-hydrogen or carbon-carbon bonds. Due to carbon's ability to catenate (form chains with other carbon atoms), millions of organic compounds are known. The ...

with the formula CHCl. This colourless liquid is poorly soluble in water but miscible with most organic solvents. It is a derivative of

benzene Benzene is an organic chemical compound with the molecular formula C6H6. The benzene molecule is composed of six carbon atoms joined in a planar ring with one hydrogen atom attached to each. Because it contains only carbon and hydrogen atoms, ...

, consisting of two adjacent

chlorine Chlorine is a chemical element with the Symbol (chemistry), symbol Cl and atomic number 17. The second-lightest of the halogens, it appears between fluorine and bromine in the periodic table and its properties are mostly intermediate betwee ...

atoms. It is mainly used as a

precursor chemical In chemistry, a precursor is a compound that participates in a chemical reaction that produces another compound. In biochemistry, the term "precursor" often refers more specifically to a chemical compound preceding another in a metabolic pathway, ...

in the synthesis of

agrochemical An agrochemical or agrichemical, a contraction of ''agricultural chemical'', is a chemical product used in industrial agriculture. Agrichemical refers to biocides ( pesticides including insecticides, herbicides, fungicides and nematicides) an ...

s, as a preferred solvent for dissolving and working with

fullerene A fullerene is an allotrope of carbon whose molecule consists of carbon atoms connected by single and double bonds so as to form a closed or partially closed mesh, with fused rings of five to seven atoms. The molecule may be a hollow sphere, ...

s, as an

insecticide Insecticides are substances used to kill insects. They include ovicides and larvicides used against insect eggs and larvae, respectively. Insecticides are used in agriculture, medicine, industry and by consumers. Insecticides are claimed to b ...

, and in softening and removing carbon-based contamination on metal surfaces.

Production and uses

1,2-Dichlorobenzene is obtained as a side-product of the production of

chlorobenzene Chlorobenzene is an aromatic organic compound with the chemical formula C6H5Cl. This colorless, flammable liquid is a common solvent and a widely used intermediate in the manufacture of other chemicals. Uses Historical The major use of chlorob ...

: : + → + 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 Steric effects arise from the spatial arrangement of atoms. When atoms come close together there is a rise in the energy of the molecule. Steric effects are nonbonding interactions that influence the shape ( conformation) and reactivity of ions ...

. The 1,3- isomer is uncommon because it is a meta- compound, while chlorine, like all halogens, is an ortho/para- director in terms of

electrophilic aromatic substitution Electrophilic aromatic substitution is an organic reaction in which an atom that is attached to an aromatic system (usually hydrogen) is replaced by an electrophile. Some of the most important electrophilic aromatic substitutions are aromatic ni ...

. It is mainly used as a precursor to 1,2-dichloro-4-nitrobenzene, an intermediate in the synthesis of

s.Gerald Booth (2007). "Nitro Compounds, Aromatic" in ''Ullmann's Encyclopedia of Industrial Chemistry'' Wiley-VCH, Weinheim, 2005. In terms of niche applications, 1,2-dichlorobenzene is a versatile, high-boiling solvent. It is a preferred solvent for dissolving and working with

s. It is an

for termites and locust borers, historically used by the

United States Forest Service The United States Forest Service (USFS) is an agency of the U.S. Department of Agriculture that administers the nation's 154 national forests and 20 national grasslands. The Forest Service manages of land. Major divisions of the agency inc ...

to combat widespread bark beetle outbreaks. 1,2-Dichlorobenzene is also used in softening and removing carbon-based contamination on metal surfaces.

Safety

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 The Occupational Safety and Health Administration'' (OSHA ) is a large regulatory agency of the United States Department of Labor that originally had federal visitorial powers to inspect and examine workplaces. Congress established the agenc ...

and the

National Institute for Occupational Safety and Health The National Institute for Occupational Safety and Health (NIOSH, ) is the United States federal agency responsible for conducting research and making recommendations for the prevention of work-related injury and illness. NIOSH is part of the C ...

have set occupational exposure limits at a ceiling of 50 ppm, over an eight-hour workday.

References

{{DEFAULTSORT:Dichlorobenzene, 1, 2- Chlorobenzenes Organochloride insecticides Halogenated solvents Aromatic solvents

Production and uses

Safety

See also

References