"DNCB" redirects here. For the Bucharest Ring Road in Romania, see Centura București.

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 intermediate for the industrial production of other compounds.[2]

Preparation and reactions

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]

By virtue of the two nitro substituents, the chloride in DNCB is particularly susceptible to nucleophilic substitution, at least relative to simple chlorobenzene. In this way, the compound is a precursor to many other compounds.[4][5][6] In one example, DNCB is as a substrate in Glutathione S-Transferase, relevant to activity assays.[7]

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.[8]

DNCB can cause contact dermatitis.[9]

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 Medical School. Archived from the original on 2010-11-03. Retrieved April 2, 2010.
  9. ^ 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.
Allikas: http://en.wikipedia.org/wiki/Dinitrochlorobenzene
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