Synthesis and isomerization of chlorinated isopentene

1-chloroisopentene was synthesized with isoprene and hydrogen chloride as raw materials in a three-phase bubbling reactor. The influence of the flow of hydrogen chloride, the reactive depth of isoprene and purging with N₂ at different time intervals after stopping loading hydrogen chloride on the conversion of isoprene and the yield of 1-chloroisopenteneand dichlorohydrins isopentane was investigated. The results showed that the appropriate reaction conditions were 85 g isoprene, 1 g cuprous chloride and 1 g acetate acid, at 320 mL/min hydrogen chloride for 1.5 h, when residual quantity of isoprene being 3%-5%(mass fraction) stopping hydrogen chloride and purging with N₂ at 120 mL/min for 1 h at 15-20℃, the conversion of isoprene and the yield of 1-chloroisopentene reached 96%-98% and 83%-85%, respectively. The equilibrium time and composition which the isomerization reached equilibrium were obtained. The equilibrium constant of 3-chloroisopentene to 1-chloroisopentene reached 9.21 at 0℃. The reaction heat of the isomerization was -9.64 kJ/mol, and low temperature was favorable for 3-chloroisopentene to 1-chloroisopentene.