2,4-Dinitrochlorobenzene
2,4-Dinitrochlorobenzene (DNCB) is an organic compound with the 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]
Names | |
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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) |
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Abbreviations | CDNB; DNCB |
ChEBI | |
ChemSpider | |
ECHA InfoCard | 100.002.321 |
EC Number |
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PubChem CID |
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UNII | |
CompTox Dashboard (EPA) |
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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 |
Refractive index (nD) |
1.5857 (60 °C) |
Hazards | |
NFPA 704 (fire diamond) | |
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 [77 °F], 100 kPa). | |
Infobox references | |
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. Base gives the dinitrophenol, ammonia the dinitroaniline, methoxide the dinitroanisole, and amines the secondary amines.
Laboratory use
DNCB is used as a substrate in GST enzyme activity assays.[4] 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).
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.[6]
DNCB can cause contact dermatitis.[7]
References
- "1-Chloro-2,4-dinitrobenzene". Sigma-Aldrich. Retrieved 8 September 2014.
- Gerald Booth (2007). "Nitro Compounds, Aromatic". Ullmann's Encyclopedia of Industrial Chemistry. Weinheim: Wiley-VCH. doi:10.1002/14356007.a17_411.
- "Synthesis of 1-chloro-2,4-dinitrobenzene - F. Ullmann, Verlag S. Hirzel Leipzig, 1908" (PDF). Retrieved 19 May 2020.
- 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. PMID 4436300.
- "Treating Warts". Harvard Health Publications. Harvard Medical School.
- "Treating warts". Harvard Medical School. Archived from the original on 2010-11-03. Retrieved April 2, 2010.
- 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.