2-Chloropropionic acid

2-Chloropropionic acid
Other names

α-chloropropanoic acid; α-chloropropionic acid
Identifiers
CAS number 598-78-7
ChemSpider 11241 Y
Jmol-3D images Image 1
Properties
Molecular formula C3H5ClO2
Molar mass 108.52 g mol−1
Appearance Colorless liquid
Density 1.18 g/mL
Melting point

-13 °C, 260 K, 9 °F
Boiling point

78 °C, 351 K, 172 °F (at 10 mmHg)
Solubility in water Miscible
Hazards
MSDS External MSDS
R-phrases R22 R26 R27 R28 R35
S-phrases (S1) (S2) S23 S26 S28 S36 S45
Main hazards Very toxic, corrosive
Flash point 101 °C
Related compounds
Related compounds Propionic acid
Chloroacetic acid
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Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa)
Infobox references

2-Chloropropionic 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.

Contents

Preparation

Enantiomerically pure (S)-2-chloropropionic acid is prepared from L-alanine via diazotization in hydrochloric acid.[1] Other α-amino acids undergo this reaction.

Reactions

Reduction of (S)-2-chloropropionic acid with lithium aluminium hydride affords (S)-2-chloropropanol, the simplest chloro-alcohol. This alcohol undergoes cyclization upon treatment with potassium hydroxide, which causes dehydrohalogenation to give the epoxide, (R)-methyloxirane.[2]

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.[3]

References

  1. ^ Koppenhoefer, B.; Schurig, V. (1993), "S-2-Chloroalkanoic Acids of High Enantiomeric Purity from (S)-2-Amino Acids: (S)-2-Chloropropanoic Acid", Org. Synth., http://www.orgsyn.org/orgsyn/orgsyn/prepContent.asp?prep=cv8p0119 ; Coll. Vol. 8: 119 
  2. ^ Koppenhoefer, B.; Schurig, V. (1993), "(R)-Alkyloxiranes of High Enantiomeric Purity from (S)-2-Chloroalkanoic Acids via (S)-2-Chloro-1-Alkanols: (R)-Methyloxirane", Org. Synth., http://www.orgsyn.org/orgsyn/orgsyn/prepContent.asp?prep=cv8p0434 ; Coll. Vol. 8: 434 
  3. ^ Simpson MG, Wyatt I, Jones HB, Gyte AJ, Widdowson PS, Lock EA. (1996). "Neuropathological changes in rat brain following oral administration of 2-chloropropionic acid.". Neurotoxicology 17 (2): 471–80. PMID 8856742.