2-Chloropropionic acid
{{Chembox
|Verifiedfields = changed
|Watchedfields = changed
|verifiedrevid = 477195788
|ImageFile = 2-Chloropropionic acid Enantiomers Structural Formulae.svg
|ImageName = 2-Chloropropionic acid
|PIN = 2-Chloropropanoic acid
|OtherNames = α-Chloropropanoic acid
α-Chloropropionic acid
|Section1={{Chembox Identifiers
|SMILES = ClC(C(=O)O)C
|InChI = 1/C3H5ClO2/c1-2(4)3(5)6/h2H,1H3,(H,5,6)
|InChIKey = GAWAYYRQGQZKCR-UHFFFAOYAW
|StdInChI_Ref = {{stdinchicite|correct|chemspider}}
|StdInChI = 1S/C3H5ClO2/c1-2(4)3(5)6/h2H,1H3,(H,5,6)
|StdInChIKey_Ref = {{stdinchicite|correct|chemspider}}
|StdInChIKey = GAWAYYRQGQZKCR-UHFFFAOYSA-N
|CASNo_Ref = {{cascite|correct|CAS}}
|CASNo = 598-78-7
|CASNo_Comment = (racemate)
|CASNo1 = 29617-66-1
|CASNo1_Comment = (S)
|CASNo2 = 7474-05-7
|CASNo2_Comment = (R)
|UNII_Ref = {{fdacite|correct|FDA}}
|UNII = ADV1WUE1NB
|ChemSpiderID_Ref = {{chemspidercite|correct|chemspider}}
|ChemSpiderID = 11241
|PubChem = 11734
|EC_number = 209-952-3
|RTECS = UE8575000
|UNNumber = 2511
|ChEMBL = 1743205
}}
|Section2={{Chembox Properties
|C=3 | H=5 | Cl=1 | O=2
|Appearance = Colorless liquid
|Density = 1.18 g/mL
|Solubility = Miscible
|MeltingPtC = -13
|BoilingPtC = 78
|BoilingPt_notes = at 10 mmHg
}}
|Section3={{Chembox Hazards
|ExternalSDS = [http://www.physchem.ox.ac.uk/MSDS/CH/2-chloropropionic_acid.html External MSDS]
|MainHazards = Toxic, corrosive
|FlashPtC = 101
|GHSPictograms = {{GHS05}}{{GHS06}}{{GHS07}}{{GHS08}}
|GHSSignalWord = Danger
|HPhrases = {{H-phrases|301|302|310|314|331|371|373}}
|PPhrases = {{P-phrases|260|261|262|264|270|271|280|301+312|301+330+331|302+350|303+361+353|304+340|305+351+338|309+311|310|311|314|321|322|330|361|363|403+233|405|501}}
}}
|Section4={{Chembox Related
|OtherCompounds = Propionic acid
Chloroacetic acid
}}
}}
2-Chloropropionic acid (2-chloropropanoic acid) is the chemical compound with the formula CH3CHClCO2H. This colorless liquid is the simplest chiral chlorocarboxylic acid, and it is noteworthy for being readily available as a single enantiomer. The conjugate base of 2-chloropropionic acid (CH3CHClCO2−), as well as its salts and esters, are known as 2-chloropropionates or 2-chloropropanoates.{{ Ullmann | year=2005|first1=Ulf-Rainer|last1=Samel|first2=Walter |last2=Kohler|first3=Armin Otto |last3=Gamer|first4=Ullrich |last4=Keuser | title = Propionic Acid and Derivatives| doi = 10.1002/14356007.a22_223 }}
Preparation
Racemic 2-chloropropionic acid is produced by chlorination of propionyl chloride followed by hydrolysis of the 2-chloropropionyl chloride. Enantiomerically pure (S)-2-chloropropionic acid can be prepared from L-alanine via diazotization in hydrochloric acid.{{cite journal|doi=10.15227/orgsyn.066.0151|title=(S)-2-Chloroalkanoic Acids of High Enantiomeric Purity from (S)-2-Amino Acids: (S)-2-Chloropropanoic Acid|journal=Organic Syntheses|year=1988|volume=66|last1 =Koppenhoefer|first1= Bernhardt | last2= Schurig|first2= Volker |page=151}} Other α-amino acids undergo this reaction.
Reactions
Reduction of (S)-2-chloropropionic acid with lithium aluminium hydride affords (S)-2-chloropropanol, the simplest chiral chloro-alcohol. This alcohol undergoes cyclization upon treatment with potassium hydroxide, which causes dehydrohalogenation to give the epoxide, (R)-propylene oxide (methyloxirane).{{cite journal | doi = 10.15227/orgsyn.066.0160| title = (R)-Alkyloxiranes of High Enantiomeric Purity from (S)-2-Chloroalkanoic Acids Via (S)-2-Chloro-1-Alkanols: (R)-Methyloxirane| journal = Organic Syntheses| year = 1988| volume = 66| page = 160|author1=Bernhard Koppenhoefer |author2=Volker Schurig}}
2-Chloropropionyl chloride reacts with isobutylbenzene to give, after hydrolysis, ibuprofen.
Safety
In general, α-halocarboxylic acids and their esters are good alkylating agents and should be handled with care. 2-Chloropropionic acid is a neurotoxin.{{cite journal| title = Neuropathological changes in rat brain following oral administration of 2-chloropropionic acid|vauthors=Simpson MG, Wyatt I, Jones HB, Gyte AJ, Widdowson PS, Lock EA| journal = Neurotoxicology| year = 1996| volume = 17| issue = 2| pages = 471–480| pmid = 8856742}}
See also
References
{{reflist}}
{{DEFAULTSORT:Chloropropionic acid, 2-}}