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2,4-Dinitrochlorobenzene

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2,4-Dinitrochlorobenzene
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
CAS Number
3D model (JSmol)
Abbreviations CDNB; DNCB
ChEBI
ChemSpider
ECHA InfoCard 100.002.321 Edit this at Wikidata
EC Number
  • 202-551-4
PubChem CID
UNII
CompTox Dashboard (EPA)
InChI
  • InChI=1S/C6H3ClN2O4/c7-5-2-1-4(8(10)11)3-6(5)9(12)13/h1-3HKey: VYZAHLCBVHPDDF-UHFFFAOYSA-N
SMILES
  • c1cc(c(cc1(=O))(=O))Cl
Properties
Chemical formula C6H3ClN2O4
Molar mass 202.55 g·mol
Appearance yellow crystals
Odor almond-like
Density 1.6867 g/cm
Melting point 54 °C (129 °F; 327 K)
Boiling point 315 °C (599 °F; 588 K)
Solubility in water Insoluble
Solubility soluble in ether, benzene, CS2
Refractive index (nD) 1.5857 (60 °C)
Hazards
NFPA 704 (fire diamond)
NFPA 704 four-colored diamondHealth 3: Short exposure could cause serious temporary or residual injury. E.g. chlorine gasFlammability 1: Must be pre-heated before ignition can occur. Flash point over 93 °C (200 °F). E.g. canola oilInstability 4: Readily capable of detonation or explosive decomposition at normal temperatures and pressures. E.g. nitroglycerinSpecial hazards (white): no code
3 1 4
Explosive limits 2–22%
Lethal dose or concentration (LD, LC):
LD50 (median dose) 1.07 g/kg (rat, oral)
Except where otherwise noted, data are given for materials in their standard state (at 25 °C , 100 kPa). ☒verify (what is  ?) Infobox references
Chemical compound

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.

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 1,3-dinitrobenzene, nitration of o-nitrochlorobenzene and the dinitration of chlorobenzene.

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.

Laboratory use

DNCB is used as a substrate in GST enzyme activity assays. 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).

Medical use

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

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.

DNCB can cause contact dermatitis.

References

  1. "1-Chloro-2,4-dinitrobenzene". Sigma-Aldrich. Retrieved 8 September 2014.
  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" (PDF). Retrieved 19 May 2020.
  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. Habig WH, Pabst MJ, Jakoby WB (1974). "Glutathione S-transferases. The first enzymatic step in mercapturic acid formation". J Biol Chem. 249 (22): 7130–7139. doi:10.1016/S0021-9258(19)42083-8. PMID 4436300.
  8. ^ "Treating Warts". Harvard Health Publications. Harvard Medical School. 21 September 2011.
  9. "Treating warts". Harvard Medical School. Archived from the original on 2010-11-03. Retrieved April 2, 2010.
  10. White SI, Friedmann PS, Moss C, Simpson JM (1986). "The effect of altering area of application and dose per unit area on sensitization by DNCB". Br. J. Dermatol. 115 (6): 663–8. doi:10.1111/j.1365-2133.1986.tb06646.x. PMID 3801307. S2CID 21476276.
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