2,3-Dichlorobutadiene

2,3-Dichlorobutadiene is a chlorinated derivative of butadiene. This colorless liquid is prone to polymerization, more so than 2-chlorobutadiene. It is used to produce specialized neoprene rubbers.

It can be prepared by the copper-catalyzed isomerization of dichlorobutynes. Alternatively dehydrochlorination of 2,3,4-trichloro-1-butene:
 * CH2=C(Cl)CH(Cl)CH2Cl +  NaOH   →  CH2=C(Cl)C(Cl)=CH2  +  NaCl  +  H2O

2,3-Dichlorobutadiene is a precursor to 2,3-diarylbutadienes.