1,4-Dichlorobut-2-ene
Chemical compound
From Wikipedia, the free encyclopedia
1,4-Dichlorobut-2-ene are organochlorine compounds with the formula ClCH2CH=CHCH2Cl. Cis and trans isomers exist. These compounds are intermediates in the industrial production of chloroprene. They are main impurity in technical grade chloroprene.[2]
| Names | |
|---|---|
| IUPAC name
1,4-Dichlorobut-2-ene | |
| Other names
trans-1,4-Dichlorobutene | |
| Identifiers | |
3D model (JSmol) |
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| ChEBI | |
| ChEMBL | |
| ChemSpider | |
| ECHA InfoCard | 100.003.437 |
| EC Number |
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| KEGG | |
PubChem CID |
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| UNII | |
| UN number | 2920 2927 2922 |
CompTox Dashboard (EPA) |
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| Properties | |
| C4H6Cl2 | |
| Molar mass | 124.99 g·molâ1 |
| Appearance | Colorless liquid |
| Density | 1.13 g/mL |
| Melting point | 1 °C (34 °F; 274 K) |
| Boiling point | 125.5 °C (257.9 °F; 398.6 K) |
| Hazards[1] | |
| GHS labelling: | |
| Danger | |
| H301, H311, H314, H330, H350, H410 | |
| P201, P202, P210, P233, P240, P241, P242, P243, P260, P264, P270, P271, P273, P280, P281, P284, P301+P310, P301+P330+P331, P302+P352, P303+P361+P353, P304+P340, P305+P351+P338, P307+P311, P308+P313, P310, P312, P314, P320, P321, P330, P361, P363, P370+P378, P391, P403+P233, P403+P235, P405, P501 | |
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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Synthesis and reactions
1,4-Dichlorobut-2-ene (both isomers) are produced by chlorination of butadiene:
- CH2=CHCH=CH2 + Cl2 â ClCH2CH=CHCH2Cl
It is isomerized to 3,4-dichlorobut-1-ene by heating to temperatures of 60â120 °C in the presence of a catalyst:
- ClCH2CH=CHCH2Cl â ClCH2CHClCH=CH2
The resulting 3,4-dichlorobut-1-ene is a precursor to chloroprene, the monomer for the synthetic rubber neoprene.[3]
1,4-Dichlorobut-2-ene is a precursor to various heterocycles.[4] The (E)-isomer is also one of the starting materials for the poriferic natural product sceptrin.[5]

