{{Chembox | ImageFile = 4-Chlorphenol.svg | ImageSize = 80 | ImageAlt = | PIN = 4-Chlorophenol | OtherNames = ''p''-Chlorophenol, ''para''-Chlorophenol |Section1={{Chembox Identifiers | CASNo = 106-48-9 | CASNo_Ref = {{Cascite|correct|CAS}} | ChEBI = 28078 | ChEMBL = 57053 | ChemSpiderID = 13875219 | DrugBank = DB13154 | KEGG = C02124 | PubChem = 4684 | EC_number = 203-402-6 | RTECS = SK2800000 | UNNumber = 2020 | UNII = 3DLC36A01X | 3DMet = B00391 | Beilstein = 507004 | Gmelin = 2902 | StdInChI=1S/C6H5ClO/c7-5-1-3-6(8)4-2-5/h1-4,8H | StdInChIKey = WXNZTHHGJRFXKQ-UHFFFAOYSA-N | SMILES = C1=CC(=CC=C1O)Cl }} |Section2={{Chembox Properties | C=6|H=5|Cl=1|O=1 | Appearance = White solid | Density = 1.2651 g/cm<sup>3</sup> at 40 °C<ref name=crc/> | MeltingPtC = 43.1 | MeltingPt_ref =<ref name=crc>Haynes, p. 3.116</ref> | BoilingPtC = 219 | BoilingPt_ref =<ref name=crc/> | RefractIndex = 1.5579<ref name=crc/> | Solubility = 27.1 g/L | pKa = 9.41<ref>Haynes, p. 5.90</ref> | MagSus = −77.7·10<sup>−6</sup> cm<sup>3</sup>/mol<ref>Haynes, p. 3.577</ref> }} |Section3={{Chembox Structure | Structure_ref =<ref>Haynes, p. 9.61</ref> | Dipole = 2.11 D }} |Section4={{Chembox Thermochemistry | Thermochemistry_ref=<ref>Haynes, pp. 5.10, 6.156</ref> | DeltaHf = −197.7 kJ·mol<sup>−1</sup> (s)<br> −181.3 kJ·mol<sup>−1</sup> (l) | DeltaHc = | Entropy = | HeatCapacity = | DeltaHfus = 14.1 kJ·mol<sup>−1</sup> }} |Section8={{Chembox Hazards | MainHazards = | FlashPtC = 121 | FlashPt_ref = <ref>Haynes, p. 16.20</ref> | AutoignitionPt = | GHSPictograms = {{GHS05}}{{GHS06}}{{GHS07}}{{GHS09}} | GHSSignalWord = Danger | HPhrases = {{H-phrases|290|301|302|312|314|332|411}} | PPhrases = {{P-phrases|234|260|261|264|270|271|273|280|301+310|301+312|301+330+331|302+352|303+361+353|304+312|304+340|305+351+338|310|312|321|322|330|363|390|391|404|405|501}} }} }} '''4-Chlorophenol''' is an organic compound with the formula C<sub>6</sub>H<sub>4</sub>ClOH. It is one of three monochlorophenol isomers. It is a colorless or white solid that melts easily and exhibits significant solubility in water. Its pK<sub>a</sub> is 9.41.
==Preparation and reaction== It is prepared by chlorination of phenol, preferably in polar solvents, which tends to yield the 4-chloro derivative. Direct chlorination of molten phenol favors the formation of 2-chlorophenol.<ref name=Ull2/>
It once was produced on a large scale as a precursor to hydroquinone.<ref name=Ull2>{{Ullmann|author1=Muller, François |author2=Caillard, Liliane |title=Chlorophenols|year=2011|doi=10.1002/14356007.a07_001.pub2}}</ref> It is a classic precursor, upon reaction with phthalic anhydride, to quinizarin.<ref>{{cite journal|journal=Org. Synth.|year=1926|volume=6|page=78|doi=10.15227/orgsyn.006.0078|title=Quinizarin|first1=L. A.|last1=Bigelow|first2=H. H.|last2=Reynolds}}</ref> The commercial dye quinizarin is produced by the reaction of phthalic anhydride and 4-chlorophenol followed by hydrolysis of the chloride.<ref name=Ullmann>{{ Ullmann | author = Bien, H.-S. | author2 = Stawitz, J. | author3 = Wunderlich, K. | title = Anthraquinone Dyes and Intermediates | doi = 10.1002/14356007.a02_355 }}</ref>
[[image:Clofibrate.svg|thumb|left|Clofibrate, a drug for controlling the high cholesterol and triacylglyceride level in the blood, is derived from 4-chlorophenol.]]{{clear-left}}
==References== {{reflist}} ==Cited sources== *{{cite book |ref=Haynes| editor= Haynes, William M. | date = 2016| title = CRC Handbook of Chemistry and Physics | edition = 97th | publisher = CRC Press | isbn = 9781498754293}}
{{DEFAULTSORT:Chlorophenol, 4-}} Category:4-Chlorophenyl compounds Category:4-Hydroxyphenyl compounds