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|Section2= |Section3= |Section4= |Section5= |Section6= |Section7= |Section8= }} Brodifacoum is a highly lethal 4-hydroxycoumarin vitamin K antagonist anticoagulant poison. In recent years, it has become one of the world's most widely used pesticides. It is typically used as a rodenticide but is also used to control larger pests such as possum.〔Eason, C.T. and Wickstrom, M. ''Vertebrate pesticide toxicology manual'', New Zealand Department of Conservation〕 Brodifacoum has an especially long half-life in the body, which ranges to several months, requiring prolonged treatment with antidotal vitamin K for both human and pet poisonings. ==Chemical synthesis== Brodifacoum is a derivative of the 4-hydroxy-coumarin group. Compound 1 is the starting ester needed to synthesize brodifacoum. To obtain this starting compound a simple Wittig condensation of ethyl chloroacetate with 4’-bromobiphenylcarboxaldehyde was accomplished. Compound 1 was transformed into 2 by consecutive hydrolysis, halogenation to form an acid chloride, and then reacted with the required lithium anion. This was done using KOH and EtOH for hydrolysis, and then adding SOCl2 for chlorination to form the acid chloride which reacted with the addition of lithium anion. Compound 2 was then transformed using organocopper chemistry to yield compound 3 with good regioselectivity of about 98%. Typically a Friedel-Crafts type cyclization would be utilized to obtain the two ring system portion of compound 4, but there were issues of low yield. Instead trifluoromethanesulfonic acid in dry benzene catalyzed the cyclization in good yield. The ketone was then reduced with sodium borohydride yielding a benzyl alcohol. Condensation with 4-hydroxycoumarin under HCl yielded compound 5, brodifacoum. 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「Brodifacoum」の詳細全文を読む スポンサード リンク
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