PREPARATION METHOD OF BIFENTHRIN

摘要

PURPOSE: A method for preparing bifenthrin is provided, to obtain bifenthrin with the improved production yield under the milder condition by employing the thioacyl dithiophosphate as an intermediate. CONSTITUTION: The method comprises the steps of reacting the 3-(2-chloro-3,3,3-trifluoro-1-propenyl)-2,2-dimethyl cyclopentane carboxylic acid alkyl ester represented by the formula 2 with the dithiophosphate represented by the formula 3 to prepare the thioacyl dithiophosphate represented by the formula 4; and reacting the thioacyl dithiophosphate of the formula 4 with the 2-methyl-biphenyl-3-yl-methanol represented by the formula 5 to prepare the bifenthrin represented by the formula 1, wherein R1 and R2 are an alkyl group of C1-C6, respectively. Preferably the first step is carried out with stirring the mixture in the presence of an amine base; and the second step is carried out in the presence of an amine base at a room temperature.