2,4-Dinitrochlorobenzene

"DNCB" redirects here. For the Bucharest Ring Road in Romania, see Centura București.
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
3D model (JSmol)
Abbreviations CDNB; DNCB
ChEBI
ChemSpider
ECHA InfoCard 100.002.321 Edit this at Wikidata
EC Number
  • 202-551-4
UNII
  • InChI=1S/C6H3ClN2O4/c7-5-2-1-4(8(10)11)3-6(5)9(12)13/h1-3H
    Key: VYZAHLCBVHPDDF-UHFFFAOYSA-N
  • c1cc(c(cc1[N+](=O)[O-])[N+](=O)[O-])Cl
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)
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):
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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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 1,3-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". 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. ^ a b "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.