Method for gas-phase synthesis for 1,2-dichloro-3,3,4,4,5,5-hexachlorocyclopentene

The invention relates to a method for gas-phase synthesis for 1,2-dichloro-3,3,4,4,5,5-hexachlorocyclopentene, which belongs to the field of chemical synthesis. According to the method disclosed by the invention, chromium, magnesium, zinc and aluminium are used as the active metals of a catalyst, hexachlorocyclopentene and chlorine are used as raw materials, AHF (anhydrous hydrogen fluoride) is used as a fluorinating agent, a reaction is performed in high-temperature gas-phase conditions, and the unreacted raw materials can be recycled. The catalyst selected in the method disclosed by the invention is good in stability, safe in synthesis process, and suitable for industrialized production. Due to recovery for hexachlorocyclopentene, the process is much optimized and the production cost is decreased, thus meeting the policy of low-energy-consumption and environment-friendly clean production of China.