1,4-Dichlorobut-2-ene

1,4-Dichlorobut-2-ene
Names
	IUPAC name 1,4-Dichlorobut-2-ene
	Other names trans-1,4-Dichlorobutene
Identifiers
CAS Number	110-57-6 ;
3D model (JSmol)	Interactive image; Interactive image;
ChEBI	CHEBI:82446;
ChEMBL	ChEMBL468582;
ChemSpider	557415 ;
ECHA InfoCard	100.003.437
EC Number	203-779-7;
KEGG	C19398;
PubChem CID	642197;
UNII	92HZ946H7Y;
UN number	2920 2927 2922
CompTox Dashboard (EPA)	DTXSID6020434 ;
	InChI InChI=1S/C4H6Cl2/c5-3-1-2-4-6/h1-2H,3-4H2 Key: FQDIANVAWVHZIR-UHFFFAOYSA-N ; InChI=1/C4H6Cl2/c5-3-1-2-4-6/h1-2H,3-4H2/b2-1+ Key: FQDIANVAWVHZIR-OWOJBTEDBY; InChI=1S/C4H6Cl2/c5-3-1-2-4-6/h1-2H,3-4H2 Key: FQDIANVAWVHZIR-UHFFFAOYSA-N;
	SMILES ClC/C=C/CCl; ClCC=CCCl;
Properties
Chemical formula	C4H6Cl2
Molar mass	124.99 g·mol−1
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
	GHS labelling:
Pictograms	;
Signal word	Danger
Hazard statements	H301, H311, H314, H330, H350, H410
Precautionary statements	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). verify (what is ?) Infobox references

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]

Synthesis and reactions

1,4-Dichlorobut-2-ene (both isomers) are produced by chlorination of butadiene:

CH₂=CHCH=CH₂ + Cl₂ → ClCH₂CH=CHCH₂Cl

It is isomerized to 3,4-dichlorobut-1-ene by heating to temperatures of 60–120 °C in the presence of a catalyst:

ClCH₂CH=CHCH₂Cl → 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]

References

^ Index no. 602-073-00-X of Annex VI, Part 3, to Regulation (EC) No 1272/2008 of the European Parliament and of the Council of 16 December 2008 on classification, labelling and packaging of substances and mixtures, amending and repealing Directives 67/548/EEC and 1999/45/EC, and amending Regulation (EC) No 1907/2006. OJEU L353, 31.12.2008, pp 1–1355 at p 473.
^ Re-evaluation of Some Organic Chemicals, Hydrazine and Hydrogen Peroxide (PDF), IARC Monographs on the Evaluation of Carcinogenic Risks to Humans 71, Lyon, France: International Agency for Research on Cancer, 1999, pp. 227–50, ISBN 92-832-1271-1.
^ Rossberg, M.; Lendle, W.; Pfleiderer, G.; Tögel, A.; Dreher, E.-L.; Langer, E.; Rassaerts, H.; Kleinschmidt, P.; Strack, H.; Cook, R.; Beck, U.; Lipper, K.-A.; Torkelson, T. R.; Löser, E.; Beutel, K.K.; Mann, T. (15 July 2006). "Chlorinated Hydrocarbons". Ullmann's Encyclopedia of Industrial Chemistry. Weinheim: Wiley-VCH. doi:10.1002/14356007.a06_233.pub2. ISBN 978-3-527-30673-2.Stewart, C. A. Jr. (1993), "Chlorocarbons, -hydrocarbons (chloroprene)", in Kroschwitz, J. I.; Howe-Grant, M. (eds.), Kirk-Othmer Encyclopedia of Chemical Technology, vol. 6 (4th ed.), New York: John Wiley, pp. 70–78.
^ Albert I. Meyers, Joseph S. Warmus, Garrett J. Dilley (1996). "3-Pyrroline". Organic Syntheses. 73: 246. doi:10.15227/orgsyn.073.0246.{{cite journal}}: CS1 maint: multiple names: authors list (link)
^ Birman, Vladimir B.; Jiang, Xun-Tian (2004), "Synthesis of Sceptrin Alkaloids", Org. Lett., 6 (14): 2369–71, doi:10.1021/ol049283g, PMID 15228281. Baran, Phil S.; Zografos, Alexandros L.; O'Malley, Daniel P. (2004), "Short Total Synthesis of (±)-Sceptrin", J. Am. Chem. Soc., 126 (12): 3726–27, doi:10.1021/ja049648s, PMID 15038721.

[1] Index no. 602-073-00-X of Annex VI, Part 3, to Regulation (EC) No 1272/2008 of the European Parliament and of the Council of 16 December 2008 on classification, labelling and packaging of substances and mixtures, amending and repealing Directives 67/548/EEC and 1999/45/EC, and amending Regulation (EC) No 1907/2006. OJEU L353, 31.12.2008, pp 1–1355 at p 473.

[2] Re-evaluation of Some Organic Chemicals, Hydrazine and Hydrogen Peroxide (PDF), IARC Monographs on the Evaluation of Carcinogenic Risks to Humans 71, Lyon, France: International Agency for Research on Cancer, 1999, pp. 227–50, ISBN 92-832-1271-1.

[3] Rossberg, M.; Lendle, W.; Pfleiderer, G.; Tögel, A.; Dreher, E.-L.; Langer, E.; Rassaerts, H.; Kleinschmidt, P.; Strack, H.; Cook, R.; Beck, U.; Lipper, K.-A.; Torkelson, T. R.; Löser, E.; Beutel, K.K.; Mann, T. (15 July 2006). "Chlorinated Hydrocarbons". Ullmann's Encyclopedia of Industrial Chemistry. Weinheim: Wiley-VCH. doi:10.1002/14356007.a06_233.pub2. ISBN 978-3-527-30673-2.Stewart, C. A. Jr. (1993), "Chlorocarbons, -hydrocarbons (chloroprene)", in Kroschwitz, J. I.; Howe-Grant, M. (eds.), Kirk-Othmer Encyclopedia of Chemical Technology, vol. 6 (4th ed.), New York: John Wiley, pp. 70–78.

[4] Albert I. Meyers, Joseph S. Warmus, Garrett J. Dilley (1996). "3-Pyrroline". Organic Syntheses. 73: 246. doi:10.15227/orgsyn.073.0246.{{cite journal}}: CS1 maint: multiple names: authors list (link)

[sceptrin-5] Birman, Vladimir B.; Jiang, Xun-Tian (2004), "Synthesis of Sceptrin Alkaloids", Org. Lett., 6 (14): 2369–71, doi:10.1021/ol049283g, PMID 15228281. Baran, Phil S.; Zografos, Alexandros L.; O'Malley, Daniel P. (2004), "Short Total Synthesis of (±)-Sceptrin", J. Am. Chem. Soc., 126 (12): 3726–27, doi:10.1021/ja049648s, PMID 15038721.

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