METHOD OF PREPARING CYPERMETHRIN AND CYFLUTHRIN ISOMERS MIXTURE Russian patent published in 1996 - IPC

FIELD: agriculture, insecticides. SUBSTANCE: method involves the preparing isomers mixture of cypermethrin and cyfluthrin with increased content of enantiomeric pairs 1S, trans-R with regard to enantiomeric pairs 1S,1R, cis-R and 1S, trans-R. Reagent 1: alpha-hydroxyphenoxyacetonitrile or its 4-fluoro-analog. Reagent 2: 3-(2,2-dichloroethynyl)-2,2-dimethylcyclopropanecarbonyl chloride. Reaction conditions: inert medium, boiling point of hydrocarbon solvent - 75-115 C followed by washing off reaction mass with the base aqueous solution. EFFECT: improved method of isomers mixture preparing. 3 cl, 2 tbl