- Source: 1,4-Dichlorobut-2-ene
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.
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.
Other reactions
1,4-Dichlorobut-2-ene is a precursor to various heterocycles.
The (E)-isomer is also one of the starting materials for the poriferic natural product sceptrin.
