2-Chloropropionic acid
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| 2-Chloropropionic acid | |
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| General | |
| Systematic name | 2-Propanoic acid |
| Other names | α-propanoic acid; α-propanoic acid |
| Molecular formula | C3H4ClO2 |
| SMILES | CC(Cl)C(O)=O |
| Molar mass | 108.52 g/mol |
| Appearance | Colorless liquid |
| CAS number | [598-78-7] |
| Properties | |
| Density and phase | 1.18 g/mL |
| Solubility in water | Miscible |
| Melting point | -13 °C |
| Boiling point | 78 °C at 10 mmHg |
| Acidity (pKa) | ? |
| Chiral rotation [α]D | 13.98° |
| Viscosity | ? cP at ?°C |
| Structure | |
| Dipole moment | ? D |
| Hazards | |
| MSDS | External MSDS |
| Main hazards | Very toxic, corrosive |
| NFPA 704 | |
| Flash point | 101 °C |
| R/S statement | R: R22 R26 R27 R28 R35 S: S1 S2 S23 S26 S28 S36 S45 |
| RTECS number | ? |
| Related compounds | Propionic acid chloroacetic acid |
| Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa) Infobox disclaimer and references |
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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 |
[edit] Preparation and use in organic synthesis
Enantiomerically pure S-2-chloropropionic acid is prepared from alanine via diazotization in hydrochloric acid.[1] Other α-amino acids undergo this reaction.
Reduction of S-2-chloropropionic acid with lithium aluminium hydride affords S-2-chloropropanol, the simplest chloro-alcohol. This alcohol undergoes cyclization upon treatment potassium hydroxide, which causes dehydrohalogenation to give the epoxide, R-methyloxirane.[2]
[edit] 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]
[edit] References
- ^ Koppenhoefer, B.; Schurig, V. “S-2-Chloroalkanoic Acids of High Enantiomeric Purity from (S)-2-Amino Acids: (S)-2-Chloropropanoic Acid” Organic Syntheses, Collected Volume 8, p.119 (1993). [1]
- ^ Koppenhoefer, B.; Schurig, V. (R)-Alkyloxiranes of Hight Enantiomeric Purity from (S)-2-Chloroalkanoic Acids via (S)-2-Chloro-1-Alkanols: (R)-Methyloxirane” Organic Syntheses, Coll. Vol. 8, p.434 (1993). [2]
- ^ 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.
