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]
Production of chloroprene
Chloroprene is a monomer for the production of synthetic rubbers such as Neoprene. It is produced from butadiene in a three-step process. The first step is the liquid- or vapour-phase chlorination of butadiene to a mixture of 3,4-dichlorobut-1-ene and 1,4-dichlorobut-2-ene (both isomers). In the second step, the mixture of 1,4-dichlorobut-2-ene and 3,4-dichlorobut-1-ene is isomerized to 3,4-dichlorobut-1-ene by heating to temperatures of 60–120 °C in the presence of a catalyst. Finally, dehydrochlorination (elimination of hydrogen chloride) of 3,4-dichlorobut-1-ene with dilute sodium hydroxide solution in the presence of polymerization inhibitors gives crude chloroprene.[3]
Other reactions
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]
^Kleinschmidt, P. (1986), "Chlorinated hydrocarbons. 6.4. 2-Chloro-1,3-butadiene", in Gerhartz, W.; Yamamoto, Y. S. (eds.), Ullmann's Encyclopedia of Industrial Chemistry, vol. A6 (5th ed.), Weinheim: VCH, pp. 315–18 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, PMID15228281. 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, PMID15038721.
