2-Chloropropionic 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.^[1]

2-Chloropropionic acid

2-Chloropropionic acid
Names
Preferred IUPAC name 2-Chloropropanoic acid
Other names α-Chloropropanoic acid α-Chloropropionic acid
Identifiers
CAS Number	598-78-7 (racemate) Y 29617-66-1 (S) 7474-05-7 (R)
3D model (JSmol)	Interactive image
ChEMBL	ChEMBL1743205
ChemSpider	11241 Y
ECHA InfoCard	100.009.049
EC Number	209-952-3
PubChem CID	11734
RTECS number	UE8575000
UNII	ADV1WUE1NB Y
UN number	2511
CompTox Dashboard (EPA)	DTXSID0021545
InChI InChI=1S/C3H5ClO2/c1-2(4)3(5)6/h2H,1H3,(H,5,6) Y Key: GAWAYYRQGQZKCR-UHFFFAOYSA-N Y InChI=1/C3H5ClO2/c1-2(4)3(5)6/h2H,1H3,(H,5,6) Key: GAWAYYRQGQZKCR-UHFFFAOYAW
SMILES ClC(C(=O)O)C
Properties
Chemical formula	C3H5ClO2
Molar mass	108.52 g·mol−1
Appearance	Colorless liquid
Density	1.18 g/mL
Melting point	−13 °C (9 °F; 260 K)
Boiling point	78 °C (172 °F; 351 K) at 10 mmHg
Solubility in water	Miscible
Hazards
Occupational safety and health (OHS/OSH):
Main hazards	Toxic, corrosive
GHS labelling:
Pictograms
Signal word	Danger
Hazard statements	H301, H302, H310, H314, H331, H371, H373
Precautionary statements	P260, P261, P262, P264, P270, P271, P280, P301+P312, P301+P330+P331, P302+P350, P303+P361+P353, P304+P340, P305+P351+P338, P309+P311, P310, P311, P314, P321, P322, P330, P361, P363, P403+P233, P405, P501
Flash point	101 °C (214 °F; 374 K)
Safety data sheet (SDS)	External MSDS
Related compounds
Related compounds	Propionic acid Chloroacetic acid
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). N verify (what is YN ?) Infobox references

Preparation

Racemic 2-chloropropionic acid is produced by chlorination of propionyl chloride followed by hydrolysis of the 2-chloropropionyl chloride.^[1] Enantiomerically pure (S)-2-chloropropionic acid can be prepared from L-alanine via diazotization in hydrochloric acid.^[2] 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).^[3]

2-Chloropropionyl chloride reacts with isobutylbenzene to give, after hydrolysis, ibuprofen.^[1]

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.^[4]

See also

• 2,2-Dichloropropionic acid