Efficient and economical synthesis of allyl chloride or 3-chloropropene [107-05-1] was made possible by the discovery in the late 1930s of a direct high temperature (300-500 • C) chlorination reaction by the Shell . This synthesis allows good yields and use of common inexpensive raw materials such as propylene and chlorine. Although World War II delayed commercial implementation of this chemistry, particularly in Europe, Shell Chemical Co. was able to begin commercial production of allyl chloride in 1945 at their refinery site near Houston, which is now Deer Park, Texas (5). In 1955, The Dow Chemical Company began commercial manufacture of allyl chloride in Freeport, Texas. Initially, for both companies, the allyl chloride product was largely converted to allyl alcohol (qv) and then to glycerol (qv); however, the emergence of epoxy resins (qv) in the 1950s caused a shift to production of epichlorohydrin from allyl chloride. Both epoxy resins and glycerol can be easily produced from epichlorohydrin (6).The direct high temperature chlorination of propylene continues to be the primary route for the commercial production of allyl chloride. The reaction results in allyl chloride selectivities of 75-80% from propylene and about 75% from chlorine. Additionally, a significant by-product of this reaction, 1,3-dichloropropene, finds commercial use as an effective nematocide when used in soil fumigation. Overall efficiency of propylene and chlorine use thus is significantly increased. Remaining by-products include 1,2-dichloropropane, 2-chloropropene, and 2-chloropropane.A second method for synthesis of allyl chloride is thermal dehydrochlorination, ie, cracking, of 1,2dichloropropane, but this method is generally less satisfactory because of low allyl chloride selectivity (50-60%) and operating temperatures of 500-600 • C (4, 7-10). The by-products of cracking are 1-chloropropene and 2-chloropropene, which have no significant commercial use.The oxychlorination of propylene to allyl chloride, using hydrogen chloride and oxygen, has also been demonstrated. However, with inferior yields, less than satisfactory catalyst life, and a complex processing scheme, (11)(12)(13)(14)(15)(16)(17)(18)(19)(20) this route to allyl chloride is not utilized commercially.