Chemistry:2,4-Dinitrochlorobenzene

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2,4-Dinitrochlorobenzene
2,4-Dinitrochlorobenzene.svg
1-chloro-2,4-dinitrobenzene.JPG
Names
Preferred IUPAC name
1-Chloro-2,4-dinitrobenzene
Other names
Dinitrochlorobenzene
Chlorodinitrobenzene
2,4-Dinitrochlorobenzene
2,4-Dinitrophenyl chloride
4-Chloro-1,3-dinitrobenzene
Identifiers
3D model (JSmol)
Abbreviations CDNB; DNCB
ChEBI
ChemSpider
EC Number
  • 202-551-4
UNII
Properties
C6H3ClN2O4
Molar mass 202.55 g·mol−1
Appearance yellow crystals
Odor almond-like
Density 1.6867 g/cm3
Melting point 54 °C (129 °F; 327 K)
Boiling point 315 °C (599 °F; 588 K)
Insoluble[1]
Solubility soluble in ether, benzene, CS2
1.5857 (60 °C)
Hazards
NFPA 704 (fire diamond)
Flammability code 1: Must be pre-heated before ignition can occur. Flash point over 93 °C (200 °F). E.g. canola oilHealth code 3: Short exposure could cause serious temporary or residual injury. E.g. chlorine gasReactivity code 4: Readily capable of detonation or explosive decomposition at normal temperatures and pressures. E.g. nitroglycerinSpecial hazards (white): no codeNFPA 704 four-colored diamond
1
3
4
Explosive limits 2–22%
Lethal dose or concentration (LD, LC):
1.07 g/kg (rat, oral)
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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Infobox references
Tracking categories (test):

2,4-Dinitrochlorobenzene (DNCB) is an organic compound with the chemical formula (O2N)2C6H3Cl. It is a yellow solid that is soluble in organic solvents. It is an important intermediate for the industrial production of other compounds.[2]

DNCB is produced commercially by the nitration of p-nitrochlorobenzene with a mixture of nitric and sulfuric acids. Other methods afford the compound less efficiently include the chlorination of dinitrobenzene, nitration of o-nitrochlorobenzene and the dinitration of chlorobenzene.[3]

Uses

By virtue of the two nitro groups, the chloride is susceptible to nucleophilic substitution. In this way, the compound is a precursor to many other compounds.[4][5][6]

Laboratory use

DNCB is used as a substrate in GST enzyme activity assays.[7] The molecule is conjugated to a single molecule of reduced glutathione which then absorbs at 340 nm. Affinity of CDNB for each class of GST varies and so it is not a good measure of activity for some forms (e.g. GSTT and GSTZ).[citation needed]

Medical use

DNCB can be used to treat warts with an effective cure rate of 80%.[8] DNCB induces an allergic immune response toward the wart-causing virus.[8]

Safety

DNCB induces a type IV hypersensitivity reaction in almost all people exposed to it, so it is used medically to assess the T cell activity in patients. This is a useful diagnostic test for immunocompromised patients. It can also be used to treat warts.[9]

DNCB can cause contact dermatitis.[10]

References

  1. "1-Chloro-2,4-dinitrobenzene". http://www.sigmaaldrich.com/catalog/product/aldrich/138630?lang=en&region=US. 
  2. Gerald Booth (2007). "Nitro Compounds, Aromatic". Ullmann's Encyclopedia of Industrial Chemistry. Weinheim: Wiley-VCH. doi:10.1002/14356007.a17_411. ISBN 978-3527306732. 
  3. "Synthesis of 1-chloro-2,4-dinitrobenzene - F. Ullmann, Verlag S. Hirzel Leipzig, 1908". https://organic-btc-ilmenau.jimdo.com/app/download/8980039020/1-Chlor-2%2C4-dinitrobenzol.pdf. 
  4. J. F. Bunnett, R. M. Conner (1960). "2,4-Dinitroiodobenzene". Organic Syntheses 40: 34. doi:10.15227/orgsyn.040.0034. 
  5. F. B. Wells, C. F. H. Allen (1935). "2,4-Dinitroaniline". Organic Syntheses 15: 22. doi:10.15227/orgsyn.015.0022. 
  6. Norman Kharasch, Robert B. Langford (1964). "2,4-Dinitrobenzenesulfenyl Chloride". Organic Syntheses 44: 47. doi:10.15227/orgsyn.044.0047. 
  7. "Glutathione S-transferases. The first enzymatic step in mercapturic acid formation". J Biol Chem 249 (22): 7130–7139. 1974. doi:10.1016/S0021-9258(19)42083-8. PMID 4436300. 
  8. 8.0 8.1 "Treating Warts". Harvard Health Publications. Harvard Medical School. 21 September 2011. http://www.health.harvard.edu/family-health-guide/treating-warts. 
  9. "Treating warts". Harvard Medical School. http://www.health.harvard.edu/fhg/updates/update0303d.shtml. 
  10. "The effect of altering area of application and dose per unit area on sensitization by DNCB". Br. J. Dermatol. 115 (6): 663–8. 1986. doi:10.1111/j.1365-2133.1986.tb06646.x. PMID 3801307.