Crotyl chloride
Chemical compound
From Wikipedia, the free encyclopedia
Crotyl chloride is an organochloride with the molecular formula C4H7Cl or H3C(CH)2CH2Cl.[1] It is a derivative of 2-butene with a chlorine atom at a terminal carbon. It exhibits cis-trans isomerism about the double bond; the (E) isomer predominates in commercial preparations.[2]
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| Names | |
|---|---|
| Preferred IUPAC name
(2E)-1-Chlorobut-2-ene | |
| Other names
1-Chloro-2-butene, 1-chlorobut-2-ene, 2-butenyl chloride, gamma-methylallyl chloride | |
| Identifiers | |
3D model (JSmol) |
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| 605304 | |
| ChemSpider | |
| ECHA InfoCard | 100.008.855 |
PubChem CID |
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| RTECS number |
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| UNII | |
CompTox Dashboard (EPA) |
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| Properties | |
| C4H7Cl | |
| Molar mass | 90.55 g·mol−1 |
| Appearance | Liquid |
| Density | 0.949 g/cm3 |
| Melting point | −65 °C (−85 °F; 208 K) |
| Boiling point | 84 °C (183 °F; 357 K) |
| Vapor pressure | 37084 mmHG |
| Hazards | |
| NFPA 704 (fire diamond) | |
| Flash point | −15 °C (5 °F; 258 K) |
| 510 °C (950 °F; 783 K) | |
| Related compounds | |
Related chloroalkenes |
Allyl chloride Methallyl chloride |
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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Preparation
It can be produced by the chlorination of crotyl alcohol by chlorinating agents such as triphenylphosphine dichloride.[2]
Applications
Treatment of crotyl halides with magnesium produces crotyl Grignard reagents. The chloride is more stable than the bromide.[3] These reagents can then be used in the Grignard reaction for crotylation of carbonyl compounds.[4]
Dehydrohalogenation of crotyl chloride was once used as a laboratory route to produce butadiene, though the pyrolysis of cyclohexene is preferred according to Organic Syntheses.[5] Crotyl chloride may be used as a model compound for other allylic hydrochlorocarbons.[6]
