:Chloroacetyl chloride
{{Distinguish|Acetyl chloride|Chloroacetic acid}}
{{chembox
| Verifiedfields = changed
| Watchedfields = changed
| verifiedrevid = 444365675
| ImageFile = Chloroacetyl chloride.svg
| ImageSize = 150px
| ImageName = Skeletal formula
| ImageFile1 = Chloroacetyl-chloride-3D-balls.png
| ImageSize1 = 170px
| ImageName1 = ball-and-stick model
| PIN = Chloroacetyl chloride
| OtherNames = 2-Chloroacetyl chloride
Chloroacetic acid chloride
Chloroacetic chloride
Monochloroacetyl chloride
|Section1={{Chembox Identifiers
| ChemSpiderID_Ref = {{chemspidercite|changed|chemspider}}
| ChemSpiderID = 13856283
| SMILES = C(C(=O)Cl)Cl
| InChI = 1/C2H2Cl2O/c3-1-2(4)5/h1H2
| InChIKey = VGCXGMAHQTYDJK-UHFFFAOYAB
| StdInChI_Ref = {{stdinchicite|changed|chemspider}}
| StdInChI = 1S/C2H2Cl2O/c3-1-2(4)5/h1H2
| StdInChIKey_Ref = {{stdinchicite|changed|chemspider}}
| StdInChIKey = VGCXGMAHQTYDJK-UHFFFAOYSA-N
| CASNo_Ref = {{cascite|correct|CAS}}
| CASNo =79-04-9
| UNII_Ref = {{fdacite|correct|FDA}}
| UNII = K5UML06YUO
| PubChem =6577
| EINECS =201-171-6
| KEGG_Ref = {{keggcite|correct|kegg}}
| KEGG = C14859
| ChEMBL = 3187685
| ChEBI = 34624
| RTECS = AO6475000
| UNNumber = 1752
}}
|Section2={{Chembox Properties
| C=2 | H=2 | Cl=2 | O=1
| Appearance =Colorless to yellow liquid
| Density =1.42 g/mL
| MeltingPtC =-22
| BoilingPtC =106
| Solubility = Reacts
| VaporPressure = 19 mmHg (20°C)
}}
|Section3={{Chembox Hazards
| ExternalSDS = [http://msds.chem.ox.ac.uk/CH/chloroacetyl_chloride.html Oxford MSDS]
| GHSPictograms = {{GHS05}}{{GHS06}}{{GHS08}}{{GHS09}}
| GHSSignalWord = Danger
| HPhrases = {{H-phrases|301|311|314|331|372|400}}
| PPhrases = {{P-phrases|260|261|264|270|271|273|280|301+310|301+330+331|302+352|303+361+353|304+340|305+351+338|310|311|312|314|321|322|330|361|363|391|403+233|405|501}}
| NFPA-H = 3
| NFPA-F = 0
| NFPA-I = 1
| FlashPt = noncombustible
| AutoignitionPt =
| PEL = none{{PGCH|0120}}
| REL = TWA 0.05 ppm (0.2 mg/m3)
}}
}}
Chloroacetyl chloride is a chlorinated acyl chloride. It is a bifunctional compound, making it a useful building block chemical.
Production
Industrially, it is produced by the carbonylation of methylene chloride, oxidation of vinylidene chloride, or the addition of chlorine to ketene.{{cite book |editor1=Zoeller, Joseph R. |editor2=Agreda, V. H. |title=Acetic acid and its derivatives |publisher=M. Dekker |location=New York |year=1993 | chapter = 15. Halogenated Derivatives | author = Paul R. Worsham |isbn=0-8247-8792-7 | pages = 288–298 | chapter-url = https://books.google.com/books?id=3MjdGp1v1YIC&pg=RA2-PA288 | chapter-format = Google Books excerpt}} It may be prepared from chloroacetic acid and thionyl chloride, phosphorus pentachloride, or phosgene.
Reactions
Chloroacetyl chloride is bifunctional—the acyl chloride easily forms esters{{OrgSynth | prep = cv3p0141 | collvol = 3 | collvolprep = 141 | year = 1955 | title = tert-Butyl acetate | author = Robert H. Baker and Frederick G. Bordwell}} and amides, while the other end of the molecule is able to form other linkages, e.g. with amines. The use of chloroacetyl chloride in the synthesis of lidocaine is illustrative:{{cite journal | journal = J. Chem. Educ. | volume = 76 | issue = 11 | year = 1999 | pages = 1557 | author = T. J. Reilly | title = The Preparation of Lidocaine | url = http://jchemed.chem.wisc.edu/Journal/Issues/1999/Nov/abs1557.html | doi = 10.1021/ed076p1557| bibcode = 1999JChEd..76.1557R | url-access = subscription }}
Applications
The major use of chloroacetyl chloride is as an intermediate in the production of herbicides in the chloroacetanilide family including metolachlor, acetochlor, alachlor and butachlor; an estimated 100 million pounds are used annually. Some chloroacetyl chloride is also used to produce phenacyl chloride, another chemical intermediate, also used as a tear gas. Phenacyl chloride is synthesized in a Friedel-Crafts acylation of benzene, with an aluminium chloride catalyst:{{OrgSynth | title = ω-Chloroisonitrosoacetophenone | author = Nathan Levin and Walter H. Hartung | collvol = 3 | collvolpages = 191 | year = 1955 | prep = cv3p0191}}
With anisole, it is used for the synthesis of venlafaxine.
Safety
Like other acyl chlorides, reaction with other protic compounds such as amines, alcohols, and water generates hydrochloric acid, making it a lachrymator.
There is no regulated permissible exposure limit set by the Occupational Safety and Health Administration. However, the National Institute for Occupational Safety and Health has set a recommended exposure limit at 0.05 ppm over an eight-hour work day.{{cite web|title=NIOSH Pocket Guide to Chemical Hazards|url=https://www.cdc.gov/niosh/npg/npgd0120.html|publisher=Centers for Disease Control and Prevention|year=2011}}