반응 단계
An earlier reference by Haszeldine, "Fluoro-olefins. Part II. Synthesis and Reaction of Some 3,3,3-Trihalogenopropenes" Journal of the Chemical Society [1953] pp. 3371-3378, describes a plethora of reactions of products derived from 1,1,1,3-tetrachloropropane. The reference describes preparation of this intermediate by reaction of carbon tetrachloride with ethylene in the presence of benzoyl peroxide. Among the numerous syntheses carried out by Haszeldine with 1,1,1,3-tetrachloropropane as the starting material are: dehydrochlorination of this starting material with 10% ethanolic potassium hydroxide to produce a mixture of 3,3,3- and 1,1,3-trichloropropene; isomerization of 3,3,3-trichloropropene to 1,1,3-trichloropropene using a variety of allylic rearrangement catalysts including antimony fluoride, concentrated hydrochloric acid, concentrated sulfuric acid, aluminum chloride, ferric chloride, ethanolic KOH and anhydrous hydrogen fluoride; chlorination of 1,1,3-trichloropropene in the presence of light to produce 1,1,1,2,3-pentachloropropane; chlorination of 3,3,3-trichloropropene to produce 1,1,1,2,3-pentachloropropane; dehydrochlorination of 1,1,1,2,3-pentachloropropane with ethanolic potassium hydroxide to produce a mixture of 2,3,3,3-tetrachloropropene and 1,1,2,3-tetrachloropropene; separation of 2,3,3,3-tetrachloropropene from 1,1,2,3-tetrachloropropene by distillation; and isomerization of 2,3,3,3-tetrachloropropene in the presence of aluminum chloride to produce 1,1,2,3-tetrachloropropene in 51% yield. Alternatively, Haszeldine discloses thermal isomerization of 2,3,3,3-tetrachloropropene to 1,1,2,3 tetrachloropropene at 180° C. in 45% yield. Based on the yields reported by Haszeldine for the above described series of steps, the overall yield obtained with his syntheses can be computed as 41.8% based on 1,1,1,3-tetrachloropropane, 10.4% based on carbon tetrachloride.
