Synthesis and Isomerization of Chlorinated Isopentene
1. Jiangsu Key Laboratory of Industrial Water-Conservation & Emission Reduction College of Chemistry and Chemical Engineering, Nanjing University of Technology, Nanjing 210009, China; 2. State Key Laboratory of Materials-Oriented Chemical Engineering, Nanjing University of Technology, Nanjing 210009, China
Abstract 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.
