:2,4-Dichlorophenol
{{cs1 config|name-list-style=vanc}}
{{chembox
| Watchedfields = changed
| verifiedrevid = 477211152
| ImageFileL1_Ref = {{chemboximage|correct|??}}
| ImageFileL1 = 2,4-Dichlorophenol.svg
| ImageNameL1 = Skeletal formula
| ImageFileR1 = 2,4-Dichlorophenol-3D-balls-B.png
| ImageNameR1 = Ball-and-stick model
| PIN = 2,4-Dichlorophenol
| OtherNames =
|Section1={{Chembox Identifiers
| KEGG_Ref = {{keggcite|correct|kegg}}
| KEGG = C02625
| InChI = 1/C6H4Cl2O/c7-4-1-2-6(9)5(8)3-4/h1-3,9H
| InChIKey = HFZWRUODUSTPEG-UHFFFAOYAU
| ChEMBL_Ref = {{ebicite|correct|EBI}}
| ChEMBL = 1143
| EINECS = 204-429-6
| Gmelin = 261170
| Beilstein = 742467
| RTECS = SK8575000
| UNNumber = 2020
| StdInChI_Ref = {{stdinchicite|correct|chemspider}}
| StdInChI = 1S/C6H4Cl2O/c7-4-1-2-6(9)5(8)3-4/h1-3,9H
| StdInChIKey_Ref = {{stdinchicite|correct|chemspider}}
| StdInChIKey = HFZWRUODUSTPEG-UHFFFAOYSA-N
| CASNo_Ref = {{cascite|correct|CAS}}
| CASNo=120-83-2
| PubChem=8449
| ChemSpiderID_Ref = {{chemspidercite|correct|chemspider}}
| ChemSpiderID = 8140
| ChEBI_Ref = {{ebicite|correct|EBI}}
| ChEBI = 16738
| UNII_Ref = {{fdacite|correct|FDA}}
| UNII = R669TG1950
| SMILES = Clc1cc(Cl)c(O)cc1
}}
|Section2={{Chembox Properties
| C=6|H=4|O=1|Cl=2
| MolarMass=
| MolarMass_notes =
| Appearance=White solid
| Odor=Phenolic
| Density=1.38 g/cm3
| MeltingPtC=43.2
| MeltingPt_ref=Haynes, p. 3.166
| BoilingPtC=210
| BoilingPt_ref=Haynes, p. 3.166
| Solubility=50 g/L
}}
|Section4={{Chembox Thermochemistry
| Thermochemistry_ref=Haynes, p. 5.12
| DeltaHf = −226.4 kJ·mol−1 (s)
−156.3 kJ·mol−1 (gas)
| DeltaHc =
| Entropy =
| HeatCapacity =
}}
|Section8={{Chembox Hazards
| ExternalSDS = [http://www.sigmaaldrich.com/MSDS/MSDS/DisplayMSDSPage.do External MSDS]
| MainHazards=
| NFPA-H = 0
| NFPA-F = 1
| NFPA-R = 0
| NFPA-S = COR
| GHSPictograms = {{GHS05}}{{GHS06}}{{GHS07}}{{GHS09}}
| GHSSignalWord = Danger
| HPhrases = {{H-phrases|302|311|314|411}}
| PPhrases = {{P-phrases|260|264|270|273|280|301+312|301+330+331|302+352|303+361+353|304+340|305+351+338|310|312|321|322|330|361|363|391|405|501}}
| FlashPtC =114
| FlashPt_ref = Haynes, p. 16.20
| AutoignitionPtC =
| ExploLimits=
| LD50=47.0 mg/kg (oral in rats)
790.0 mg/kg (Dermal exposure in mammals)
| PEL=
}}
}}
2,4-Dichlorophenol (2,4-DCP) is a chlorinated derivative of phenol with the molecular formula Cl2C6H3OH. It is a white solid that is mildly acidic (pKa = 7.9). It is produced on a large scale as a precursor to the herbicide 2,4-dichlorophenoxyacetic acid (2,4-D).
Production and use
2,4-DCP is produced by chlorination of phenol.{{Ullmann|author1=François Muller |author2=Liliane Caillard|title=Chlorophenols|year=2011|doi=10.1002/14356007.a07_001.pub2}}
Annual worldwide production is estimated at 88 million pounds.Desmurs J, Ratton S. Chlorophenols. In: Kirk-Othmer Encyclopedia of Chemical Technology, 4th Edition. Kroschwitz JI, Howe-Grant M, eds. New York: John Wiley and Sons, 1993;6:156–168 It is also a photo-degradation product of the common antibacterial and antifungal agent triclosan along with the dioxin 2,8-dichlorodibenzo-p-dioxin.{{cite journal |vauthors=Singer H, Muller S, Tixier C, Pillonel L |title=Triclosan: occurrence and fate of a widely used biocide in the aquatic environment: field measurements in wastewater treatment plants, surface waters, and lake sediments. |journal=Environ Sci Technol |volume=36 |issue=23 |pages=4998–5004 |year=2002 |pmid=12523412 |doi=10.1021/es025750i|bibcode=2002EnST...36.4998S }}{{cite journal |vauthors=Latch DE, Packer JL, Stender BL, VanOverbeke J, Arnold WA, McNeill K |title=Aqueous photochemistry of triclosan: formation of 2,4-dichlorophenol, 2,8-dichlorodibenzo-p-dioxin, and oligomerization products |journal=Environ. Toxicol. Chem. |volume=24 |issue=3 |pages=517–25 |year=2005 |pmid=15779749|doi=10.1897/04-243R.1|s2cid=19322739 }}
Safety
The LD50 is 580 mg/kg (rats, oral). Liquid (molten) 2,4-DCP is readily absorbed through the skin.{{cite journal |vauthors=Kintz P, Tracqui A, Mangin P |title=Accidental death caused by the absorption of 2,4-dichlorophenol through the skin |journal=Arch. Toxicol. |volume=66 |issue=4 |pages=298–9 |year=1992 |pmid=1514931 |doi= 10.1007/BF02307178|s2cid=23764834 }} Solid 2,4-DCP does not readily absorb through skin and has a lower NFPA H=3 rating (versus H=4 for molten 2,4-DCP). This is primarily caused by instantaneous kidney failure, liver failure, and failure of various other organs.{{dubious|date=July 2020}}