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
CAS Number	97-00-7  Y
3D model (JSmol)	Interactive image
Abbreviations	CDNB; DNCB
ChEBI	CHEBI:34718  N
ChemSpider	5  Y
ECHA InfoCard	100.002.321
EC Number	202-551-4
PubChem CID	6
UNII	GE3IBT7BMN  Y
CompTox Dashboard (EPA)	DTXSID6020278
InChI InChI=1S/C6H3ClN2O4/c7-5-2-1-4(8(10)11)3-6(5)9(12)13/h1-3H Key: VYZAHLCBVHPDDF-UHFFFAOYSA-N
SMILES c1cc(c(cc1[N+](=O)[O-])[N+](=O)[O-])Cl
Properties
Chemical formula	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)
Solubility in water	Insoluble [1]
Solubility	soluble in ether, benzene, CS2
Refractive index (nD)	1.5857 (60 °C)
Hazards
NFPA 704 (fire diamond)	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 [77 °F], 100 kPa). N  verify  (what is  YN ?) Infobox references

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. For example, the chloride can be replaced by iodide easily. ^{[4] [5] [6]}

Reaction of DNCB with ammonia gives 2,4-dinitrochloroaniline, again a versatile precursor. ^[2]

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.