Chlorobenzene

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Chlorobenzene
Chlorobenzene Chlorobenzene2.svg
Chlorobenzene
Chlorobenzene Chlorobenzene-3D-vdW.png
Chlorobenzene
Chlorobenzene.png
Names
Preferred IUPAC name
Chlorobenzene
Other names
Phenyl chloride, monochlorobenzene [1]
Identifiers
3D model (JSmol)
3DMet
AbbreviationsPhCl
605632
ChEBI
ChEMBL
ChemSpider
ECHA InfoCard 100.003.299 OOjs UI icon edit-ltr-progressive.svg
EC Number
  • 203-628-5
26704
KEGG
PubChem CID
RTECS number
  • CZ0175000
UNII
UN number 1134
  • InChI=1S/C6H5Cl/c7-6-4-2-1-3-5-6/h1-5H Yes check.svgY
    Key: MVPPADPHJFYWMZ-UHFFFAOYSA-N Yes check.svgY
  • InChI=1/C6H5Cl/c7-6-4-2-1-3-5-6/h1-5H
    Key: MVPPADPHJFYWMZ-UHFFFAOYAG
  • Clc1ccccc1
Properties
C6H5Cl
Molar mass 112.56 g/mol
Appearancecolorless liquid
Odor almond-like [2]
Density 1.11 g/cm3, liquid
Melting point −45.58 °C (−50.04 °F; 227.57 K)
Boiling point 131.70 °C (269.06 °F; 404.85 K)
0.5 g l−1 in water at 20 °C
Solubility in other solventssoluble in most organic solvents
Vapor pressure 9 mmHg [2]
−69.97·10−6 cm3/mol
1.52138
Viscosity 0.7232
Hazards
Occupational safety and health (OHS/OSH):
Main hazards
Low to moderate hazard [3]
GHS labelling:
GHS-pictogram-flamme.svg GHS-pictogram-exclam.svg GHS-pictogram-pollu.svg
Warning
H226, H302, H305, H315, H332, H411
P210, P233, P240, P241, P242, P243, P261, P264, P271, P273, P280, P302+P352, P303+P361+P353, P304+P312, P304+P340, P312, P321, P332+P313, P362, P370+P378, P391, P403+P235, P501
NFPA 704 (fire diamond)
NFPA 704.svgHealth 2: Intense or continued but not chronic exposure could cause temporary incapacitation or possible residual injury. E.g. chloroformFlammability 3: Liquids and solids that can be ignited under almost all ambient temperature conditions. Flash point between 23 and 38 °C (73 and 100 °F). E.g. gasolineInstability 0: Normally stable, even under fire exposure conditions, and is not reactive with water. E.g. liquid nitrogenSpecial hazards (white): no code
2
3
0
Flash point 29 °C (84 °F; 302 K)
Explosive limits 1.3%-9.6% [2]
Lethal dose or concentration (LD, LC):
2290 mg/kg (rat, oral)

590 mg/kg (mouse, orally) [4]
2250 mg/kg (rabbit, oral)
2300 mg/kg (mouse, oral)
2250 mg/kg (guinea pig, oral) [5]

Contents

8000 ppm (cat, 3 hr) [5]
NIOSH (US health exposure limits):
PEL (Permissible)
TWA 75 ppm (350 mg/m3) [2]
REL (Recommended)
none [2]
IDLH (Immediate danger)
1000 ppm [2]
Related compounds
Related Halobenzenes
Fluorobenzene
Bromobenzene
Iodobenzene
Related compounds
benzene
1,4-dichlorobenzene
Supplementary data page
Chlorobenzene (data page)
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
Yes check.svgY  verify  (what is  Yes check.svgYX mark.svgN ?)

Chlorobenzene (abbreviated PhCl) is an aryl chloride and the simplest of the chlorobenzenes, consisting of a benzene ring substituted with one chlorine atom. Its chemical formula is C6H5Cl. This colorless, flammable liquid is a common solvent and a widely used intermediate in the manufacture of other chemicals. [6]

Uses

Chlorobenzene is used as a high-boiling solvent in industrial applications as well as in the laboratory. [7]

Chlorobenzene is nitrated on a large scale to give a mixture of 2-nitrochlorobenzene and 4-nitrochlorobenzene, which are separated. These mononitrochlorobenzenes are converted to related 2-nitrophenol, 2-nitroanisole, bis(2-nitrophenyl)disulfide, and 2-nitroaniline by nucleophilic displacement of the chloride, with respectively sodium hydroxide, sodium methoxide, sodium disulfide, and ammonia. The conversions of the 4-nitro derivative are similar. [8]

Historical

The major use of chlorobenzene is as an intermediate in the production of herbicides, dyestuffs, and rubber.

Chlorobenzene once was used in the manufacture of pesticides, most notably DDT, by reaction with chloral (trichloroacetaldehyde), but this application has declined with the diminished use of DDT. At one time, chlorobenzene was the main precursor for the manufacture of phenol: [9]

C6H5Cl + NaOH → C6H5OH + NaCl

The reaction also has a byproduct of salt. The reaction is known as the Dow process, with the reaction carried out at 350 °C using fused sodium hydroxide without solvent. Labeling experiments show that the reaction proceeds via elimination/addition, through benzyne as the intermediate.

Production

It was first described in 1851. Chlorobenzene is manufactured by chlorination of benzene in the presence of a catalytic amount of Lewis acid such as ferric chloride, sulfur dichloride, and anhydrous aluminium chloride: [6]

Chlorination benzene.svg

The catalyst enhances the electrophilicity of the chlorine. Because chlorine is electronegative, C6H5Cl exhibits somewhat decreased susceptibility to further chlorination. Industrially the reaction is conducted as a continuous process to minimize the formation of dichlorobenzenes.

Laboratory routes

Chlorobenzene is producible from aniline via benzenediazonium chloride, otherwise known as the Sandmeyer reaction.

Safety

Chlorobenzene exhibits "low to moderate" toxicity as indicated by its LD50 of 2.9 g/kg. [7] The Occupational Safety and Health Administration has set a permissible exposure limit at 75 ppm (350 mg/m3) over an eight-hour time-weighted average for workers handling chlorobenzene. [10]

Toxicology and biodegradation

Chlorobenzene can persist in soil for several months, in air for about 3.5 days, and in water for less than one day. Humans may be exposed to this agent via breathing contaminated air (primarily via occupational exposure), consuming contaminated food or water, or by coming into contact with contaminated soil (typically near hazardous waste sites). However, because it has only been found at 97 out of 1,177 NPL hazardous waste sites, it is not considered a widespread environmental contaminant. The bacterium Rhodococcus phenolicus degrades chlorobenzene, dichlorobenzene and phenol as sole carbon sources. [11]

Upon entering the body, typically via contaminated air, chlorobenzene is excreted both via the lungs and the urinary system.

On other planets

Chlorobenzene has been detected in a sedimentary rock on Mars. [12] It was speculated that the chlorobenzene might have been produced when the sample was heated in the instrument sampling chamber. The heating would have triggered a reaction of organics in the Martian soil, which is known to contain perchlorate.

Related Research Articles

<span class="mw-page-title-main">Phenol</span> Organic compound (C6H5OH)

Phenol is an aromatic organic compound with the molecular formula C6H5OH. It is a white crystalline solid that is volatile. The molecule consists of a phenyl group bonded to a hydroxy group. Mildly acidic, it requires careful handling because it can cause chemical burns.

<span class="mw-page-title-main">1,4-Dichlorobenzene</span> Chemical compound

1,4-Dichlorobenzene (1,4-DCB, p-DCB, or para-dichlorobenzene, sometimes abbreviated as PDCB or para) is an aryl chloride and isomer of dichlorobenzene with the formula C6H4Cl2. This colorless solid has a strong odor. The molecule consists of a benzene ring with two chlorine atoms (replacing hydrogen atoms) on opposing sites of the ring.

Chloromethane, also called methyl chloride, Refrigerant-40, R-40 or HCC 40, is an organic compound with the chemical formula CH3Cl. One of the haloalkanes, it is a colorless, sweet-smelling, flammable gas. Methyl chloride is a crucial reagent in industrial chemistry, although it is rarely present in consumer products, and was formerly utilized as a refrigerant. Most chloromethane is biogenic.

In organic chemistry, an aryl halide is an aromatic compound in which one or more hydrogen atoms, directly bonded to an aromatic ring are replaced by a halide. The haloarene are different from haloalkanes because they exhibit many differences in methods of preparation and properties. The most important members are the aryl chlorides, but the class of compounds is so broad that there are many derivatives and applications.

<span class="mw-page-title-main">Sulfonic acid</span> Organic compounds with the structure R−S(=O)2−OH

In organic chemistry, sulfonic acid refers to a member of the class of organosulfur compounds with the general formula R−S(=O)2−OH, where R is an organic alkyl or aryl group and the S(=O)2(OH) group a sulfonyl hydroxide. As a substituent, it is known as a sulfo group. A sulfonic acid can be thought of as sulfuric acid with one hydroxyl group replaced by an organic substituent. The parent compound is the parent sulfonic acid, HS(=O)2(OH), a tautomer of sulfurous acid, S(=O)(OH)2. Salts or esters of sulfonic acids are called sulfonates.

Chloral, also known as trichloroacetaldehyde or trichloroethanal, is the organic compound with the formula Cl3CCHO. This aldehyde is a colourless liquid that is soluble in a wide range of solvents. It reacts with water to form chloral hydrate, a once widely used sedative and hypnotic substance.

Benzyl chloride, or α-chlorotoluene, is an organic compound with the formula C6H5CH2Cl. This colorless liquid is a reactive organochlorine compound that is a widely used chemical building block.

Chlorotoluenes are aryl chlorides based on toluene in which at least one aromatic hydrogen atom is replaced with a chlorine atom. They have the general formula C7H8–nCln, where n = 1–5 is the number of chlorine atoms.

<span class="mw-page-title-main">Disulfur dichloride</span> Chemical compound

Disulfur dichloride is the inorganic compound of sulfur and chlorine with the formula S2Cl2. It is an amber oily liquid.

<span class="mw-page-title-main">1,2-Dichlorobenzene</span> Chemical compound

1,2-Dichlorobenzene, or orthodichlorobenzene (ODCB), is an aryl chloride and isomer of dichlorobenzene 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 atoms.

1,2,4-Trichlorobenzene is an organochlorine compound, one of three isomers of trichlorobenzene. It is a derivative of benzene with three chloride substituents. It is a colorless liquid used as a solvent for a variety of compounds and materials.

<span class="mw-page-title-main">Hexachlorobutadiene</span> Chemical compound

Hexachlorobutadiene, (often abbreviated as "HCBD") Cl2C=C(Cl)C(Cl)=CCl2, is a colorless liquid at room temperature that has an odor similar to that of turpentine. It is a chlorinated aliphatic diene with niche applications but is most commonly used as a solvent for other chlorine-containing compounds. Structurally, it has a 1,3-butadiene core, but fully substituted with chlorine atoms.

<span class="mw-page-title-main">4-Nitrochlorobenzene</span> Chemical compound

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 antioxidants commonly found in rubber. Other isomers with the formula ClC6H4NO2 include 2-nitrochlorobenzene and 3-nitrochlorobenzene.

<span class="mw-page-title-main">1,3,5-Trichlorobenzene</span> Chemical compound

1,3,5-Trichlorobenzene is an organochlorine compound. It is one of the three isomers of trichlorobenzene. Being more symmetrical than the other isomers, it exists as colourless crystals whereas the other isomers are liquids at room temperature.

Rhodococcus phenolicus is a bacterium species in the genus Rhodococcus. Phenolicus comes from Neo-Latin noun phenol -olis, phenol; Latin masculine gender suff. -icus, suffix used in adjectives with the sense of belonging to; Neo-Latin masculine gender adjective phenolicus, belonging to phenol. This species is able to degrade phenol as sole carbon source.

The Raschig–Hooker process is a chemical process for the production of chlorobenzene and phenol.

<span class="mw-page-title-main">2-Nitrochlorobenzene</span> Chemical compound

2-Nitrochlorobenzene is an organic compound with the formula ClC6H4NO2. It is one of three isomeric nitrochlorobenzenes. It is a yellow crystalline solid that is important as a precursor to other compounds due to its two functional groups.

<span class="mw-page-title-main">3-Nitrochlorobenzene</span> Chemical compound

3-Nitrochlorobenzene is an organic compound with the formula C6H4ClNO2. It is a yellow crystalline solid that is important as a precursor to other compounds due to the two reactive sites present on the molecule.

<span class="mw-page-title-main">1,3-Dichlorobenzene</span> Chemical compound

1,3-Dichlorobenzene (also known as meta-dichlorobenzene) is an aryl chloride and isomer of dichlorobenzene with the formula C6H4Cl2. It is the least common of the three isomers of dichlorobenzene, and it is a colorless liquid that is insoluble in water. It is produced as a minor byproduct of the chlorination of benzene, but can also be prepared in a directed manner by the Sandmeyer reaction of 3-chloroaniline. It also arises from the isomerization of the other dichlorobenzenes at high temperature.

1,2,3-Trichlorobenzene is an organochlorine compound with the chemical formula C6H3Cl3. This is one of three isomers of trichlorobenzene; the two others are 1,2,4-Trichlorobenzene and 1,3,5-Trichlorobenzene.

References

  1. Pubchem. "Chlorobenzene". pubchem.ncbi.nlm.nih.gov. Retrieved 2022-08-21.
  2. 1 2 3 4 5 6 NIOSH Pocket Guide to Chemical Hazards. "#0121". National Institute for Occupational Safety and Health (NIOSH).
  3. Chlorobenzene toxicity
  4. Chlorobenzene: LD50
  5. 1 2 "Chlorobenzene". Immediately Dangerous to Life or Health Concentrations (IDLH). National Institute for Occupational Safety and Health (NIOSH).
  6. 1 2 U. Beck, E. Löser "Chlorinated Benzenes and other Nucleus-Chlorinated Aromatic Hydrocarbons" Ullmann's Encyclopedia of Industrial Chemistry, 2012, Wiley-VCH, Weinheim. doi : 10.1002/14356007.o06_o03
  7. 1 2 Rossberg, Manfred; Lendle, Wilhelm; Pfleiderer, Gerhard; Tögel, Adolf; Dreher, Eberhard-Ludwig; Langer, Ernst; Rassaerts, Heinz; Kleinschmidt, Peter; Strack, Heinz; Cook, Richard; Beck, Uwe; Lipper, Karl-August; Torkelson, Theodore R.; Löser, Eckhard; Beutel, Klaus K.; Mann, Trevor (2006). "Chlorinated Hydrocarbons". Ullmann's Encyclopedia of Industrial Chemistry. doi:10.1002/14356007.a06_233.pub2. ISBN   3527306730.
  8. Gerald Booth (2007). "Nitro Compounds, Aromatic". Ullmann's Encyclopedia of Industrial Chemistry. Weinheim: Wiley-VCH. doi:10.1002/14356007.a17_411. ISBN   978-3527306732.
  9. Weber, Manfred; Weber, Markus; Kleine-Boymann, Michael (2004). "Phenol". Ullmann's Encyclopedia of Industrial Chemistry. doi:10.1002/14356007.a19_299.pub2. ISBN   3527306730.
  10. CDC - NIOSH Pocket Guide to Chemical Hazards
  11. Rehfuss, M.; Urban, J. (2005). "Rhodococcus phenolicus sp. nov., a novel bioprocessor isolated actinomycete with the ability to degrade chlorobenzene, dichlorobenzene and phenol as sole carbon sources". Systematic and Applied Microbiology. 28 (8): 695–701. doi:10.1016/j.syapm.2005.05.011. PMID   16261859. Erratum: Rehfuss, M. (2006). "Erratum to "Rhodococcus phenolicus sp. nov., a novel bioprocessor isolated actinomycete with the ability to degrade chlorobenzene, dichlorobenzene and phenol as sole carbon sources" [Systematic and Applied Microbiology 28 (2005) 695–701]". Systematic and Applied Microbiology. 29 (2): 182. doi: 10.1016/j.syapm.2005.11.005 .
  12. Freissinet, C.; et al. (2015). "Organic molecules in the sheepbed mudstone, gale crater, mars". Journal of Geophysical Research: Planets. 120 (3): 495–514. Bibcode:2015JGRE..120..495F. doi:10.1002/2014JE004737. PMC   4672966 . PMID   26690960.