Reference

Method for preparation of bifenthrin

Method for preparation of bifenthrin. Cho, Gwang Nim; Lee, Gi In; Park, Min Seop; Sim, Yeong Gi (Korea Research Institute of Chemical Technology, S. Korea). Repub. Korean Kongkae Taeho Kongbo KR 2003041410 A 27 May 2003, No pp. given (Korean). (Korea, Republic Of). CODEN: KRXXA7.Several reagents with their cas registry numbers 76350-90-8 and 82657-04-3 are used here. CLASS: ICM: C07C069-743. APPLICATION: KR 2001-72183 20 Nov 2001. DOCUMENT TYPE: Patent CA Section: 24 (Alicyclic Compounds) A method for prepg. bifenthrin is provided, to obtain bifenthrin with the improved prodn. yield under the milder condition by employing the thioacyl dithiophosphate as an intermediate. The method comprises the steps of reacting the 3-(2-chloro-3,3,3-trifluoro-1-propenyl)-2,2-dimethylcyclopentane carboxylic acid alkyl ester represented by the formula 2 with the dithiophosphate represented by the formula 3 to prep. 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 prep. the bifenthrin represented by the formula 1, wherein R1 and R2 are an alkyl group of C1-C6, resp. Preferably the first step is carried out with stirring the mixt. in the presence of an amine base; and the second step is carried out in the presence of an amine base at a room temp. .