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|Section2= |Section7= }} Hexachlorocyclopentadiene, also known as C-56, is an organochlorine compound that is a precursor to several pesticides. This colourless liquid is an inexpensive reactive diene. Many of its derivatives proved to be highly controversial, as studies showed them to be persistent organic pollutants. Collectively, the pesticides derived from hexachlorocyclopentadiene are called the cyclodienes. An estimated 270,000 tons were produced until 1976, and some are still manufactured by Velsicol Chemical Corporation in the US and by Jiangsu Anpon Electrochemicals Co. in China. 〔Robert L. Metcalf “Insect Control” in Ullmann’s Encyclopedia of Industrial Chemistry” Wiley-VCH, Wienheim, 2002. 〕 ==Synthesis and applications== Hexachlorocyclopentadiene is prepared by chlorination of cyclopentadiene to give 1,1,2,3,4,5-octachlorocyclopentane, which in a second step undergoes dehydrochlorination:〔Dieter Hönicke, Ringo Födisch, Peter Claus, Michael Olson “Cyclopentadiene and Cyclopentene” Ullmann's Encyclopedia of Industrial Chemistry 2002, Wiley-VCH, Weinheim. 〕 :C5H6 + 6 Cl2 → C5H2Cl8 + 4 HCl :C5H2Cl8 → C5Cl6 + 2 HCl Hexachlorocyclopentadiene readily undergoes the Diels-Alder reaction to give a variety of adducts that were commercialized as pesticides. The main derivatives are: *aldrin from norbornadiene (the related dieldrin is a metabolite of aldrin) *bromodan from allyl bromide *chlordane from cyclopentadiene, followed by chlorination *endrin from acetylene, followed by cyclopentadiene, followed by epoxidation *heptachlor from cyclopentadiene, followed by monochlorination *isobenzan from dihydrofuran followed by chlorination *endosulfan from 1,4-dihydroxy-2-butene, followed by esterification with SOCl2 Additionally hexachlorocyclopentadiene is the precursor to the pesticides mirex and kepone, although these are not classified as cyclodienes. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「hexachlorocyclopentadiene」の詳細全文を読む スポンサード リンク
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