Study On The Synthesis Of 3',4',5'-trifluoro-1,1'-biphenyl-2-amine

Fluxapyroxad is a kind of new fungicide with great market prospect.In order to avoid the disadvantages of difficult separation of products,high-cost,and environmental pollution in the synthesis of its key intermediate3',4',5'-trifluoro-1,1'-biphenyl-2-amine,it is important to design a new,green and efficient synthetic routes for 3',4',5'-trifluoro-[1,1'-biphenyl]-2-amine.This thesis was divided into two chapters:In the first chapter,fluxapyroxad and the synthetic routes of its key intermediate 3',4',5'-trifluoro-1,1'-biphenyl-2-amine were reviewed.In the second chapter the preparation of 3',4',5'-trifluoro-1,1'-biphenyl-2-amine was investigated and two new synthetic routes for3',4',5'-trifluoro-1,1'-biphenyl-2-carbonitrile were designed.?1?3',4',5'-trifluoro-1,1'-biphenyl-2-carbonitrile was prepared from 5-bromo-1,2,3-trifluorobenzene and 2-chlorobenzonitrile by Grignard reaction and Kumada couple reaction.?2?5-bromo-1,2,3-trifluorobenzene reacted with trimethylborate to obtain?3,4,5-trifluorophenyl?boronic acid.3',4',5'-trifluoro-1,1'-biphenyl-2-carbonitrilewaspreparedfrom?3,4,5-trifluorophenyl?boronic acid and 2-chlorobenzonitrile by Suzuki couple reaction.Finally,3',4',5'-trifluoro-1,1'-biphenyl-2-carbonitrile reacted with H₂O₂ and NaClO through hydrolysis reaction and Hoffman reaction to obtain 3',4',5'-trifluoro-1,1'-biphenyl-2-amine.The yield of two routes were34%and 49%,respectively.The advantages of the second route reduced the cost,simplified the operation,avoided toxic reagents with a certain industrialization prospect.