View source for Benzyl chloride

{{distinguish|benzoyl chloride}}
{{chembox
| verifiedrevid = 322349884
| Name = Benzyl chloride
| ImageFileL1 = Benzyl_chloride.png
|   ImageSizeL1 = 70px 
|   ImageNameL1 = Benzyl chloride
| ImageFileR1 = Benzyl-chloride-3D-vdW.png
| IUPACName = (Chloromethyl)benzene
|   OtherNames = α-Chlorotoluene
| Section1 = {{Chembox Identifiers
|   InChI = 1/C7H7Cl/c8-6-7-4-2-1-3-5-7/h1-5H,6H2
|   InChIKey = KCXMKQUNVWSEMD-UHFFFAOYAV
| CASNo = 100-44-7
|    CASNo_Ref = {{cascite}}
|   EC-number = 202-853-6
|   ChemSpiderID = 7222
|   PubChem = 7503
|   SMILES = ClCc1ccccc1
  }}
| Section2 = {{Chembox Properties
|   Formula = C<sub>7</sub>H<sub>7</sub>Cl
|   MolarMass = 126.58 g/mol
|   Density = 1.100 g/cm<sup>3</sup>
|   MeltingPt = −39 °C
|   BoilingPt = 179 °C
  }}
| Section7 = {{Chembox Hazards
|   ExternalMSDS = [http://ptcl.chem.ox.ac.uk/MSDS/BE/benzyl_chloride.html External MSDS]
|   EUIndex = 602-037-00-3
  }}
}}

'''Benzyl chloride''', or α-chlorotoluene, is an [[organic compound]] with the [[chemical formula|formula]] [[phenyl|C<sub>6</sub>H<sub>5</sub>]]CH<sub>2</sub>Cl. This colourless liquid is a reactive [[organochlorine compound]] that is a widely used chemical building block.

==Preparation==
Benzyl chloride is prepared industrially by the gas-phase [[photochemical reaction|photochemical]] reaction of [[toluene]] with [[chlorine]]:<ref name=Ullmann>M. Rossberg et al. “Chlorinated Hydrocarbons” in Ullmann’s Encyclopedia of Industrial Chemistry 2006, Wiley-VCH, Weinheim.  {{DOI|10.1002/14356007.a06_233.pub2}}</ref>
:C<sub>6</sub>H<sub>5</sub>CH<sub>3</sub>  +  Cl<sub>2</sub>   →   C<sub>6</sub>H<sub>5</sub>CH<sub>2</sub>Cl  +  HCl
In this way, approximately 100,000 tonnes are produced annually.  The reaction proceeds via [[free radical halogenation|free radical]], involving the intermediacy of the chlorine atoms.<ref>{{VogelOrganic5th|page = 864}}.</ref>  Side products of the reaction include [[benzal chloride]] and [[benzotrichloride]].

Other methods exist, such as the [[Blanc chloromethylation]] of [[benzene]]. Benzyl chloride was first prepared from treatment of [[benzyl alcohol]] with  [[hydrochloric acid]].

==Uses and reactions==
Industrially, benzyl chloride is the precursor to benzyl esters which are used as used as [[plasticizer]], flavorants, and perfumes.  Phenylacetic acid, a precursor to pharmaceuticals, arises via benzyl cyanide, which is generated by treatment of benzyl chloride with sodium cyanide. [[Quaternary ammonium salt]]s, used as [[surfactant]]s, are readily formed by alkylation of [[tertiary amine]]s with benzyl chloride.<ref name=Ullmann/>  

In [[organic synthesis]], benzyl chloride is used for the introduction of the [[benzyl]] [[protecting group]] for [[alcohol]]s, yielding the corresponding benzyl ether, and [[carboxylic acid]]s, yielding the corresponding benzyl ester.  [[Benzoic acid]] (C<sub>6</sub>H<sub>5</sub>COOH) can be prepared by oxidation of benzyl chloride in the presence of alkaline KMnO<sub>4</sub>

C<sub>6</sub>H<sub>5</sub>CH<sub>2</sub>Cl  +  2 KOH  +  2 [O]  →  C<sub>6</sub>H<sub>5</sub>COOK  +  KCl  +  H<sub>2</sub>O

It may be used in the synthesis of amphetamine-class drugs, and for this reason sales of benzyl chloride are monitored as a [[DEA list of chemicals|List II]] drug precursor chemical by the US [[Drug Enforcement Administration]].

Benzyl chloride also reacts readily with metallic [[magnesium]] to produce a [[Grignard reagent|Grignard Reagent]].<ref>{{OrgSynth | author = Henry Gilman and W. E. Catlin | title = n-Propylbenzene | collvol = 1 | collvolpages = 471 | year = 1941 | prep = cv1p0471}}</ref> It is preferable over [[benzyl bromide]] for the preparation of benzylic Grignard reagent, since the reaction of the bromide with magnesium tends to form the Wurtz-coupling product, 1,2-diphenylethane.

==Safety==
Benzyl chloride is an [[alkylating agent]].  Indicative of its high reactivity (relative to alkyl chlorides), benzyl chloride reacts with water in a [[hydrolysis]] reaction to form [[benzyl alcohol]] and [[hydrochloric acid]].  Since benzyl chloride is quite [[Volatility (chemistry)|volatile]] at room temperature, it can easily reach the mucous membranes where the hydrolysis takes place with production of [[hydrochloric acid]]. This explains why benzyl chloride is a [[lachrymatory agent|lachrymator]] and has been used as a [[Chemical warfare|war gas]]. It is also very irritating to the skin.

==References==
{{reflist}}

==External links==
{{commonscat|Benzyl chloride}}
*{{ICSC|0016|00}}
*{{SIDS|name=benzyl chloride|id=100447}}

[[Category:Organochlorides]]
[[Category:Aromatic compounds]]
[[Category:Lachrymatory agents]]
[[Category:DEA List II chemicals]]
[[Category:IARC Group 2A carcinogens]]

[[de:Benzylchlorid]]
[[et:Bensüülkloriid]]
[[fr:Chlorure de benzyle]]
[[nl:Benzylchloride]]
[[ja:塩化ベンジル]]
[[pt:Cloreto de benzila]]
[[ru:Бензилхлорид]]
[[fi:Bentsyylikloridi]]
[[zh:氯化苄]]
[[Category:2Fix]]