摘要 |
Crystalline pyrethroid isomers or enantiomer pairs are converted to more pesticidally active isomers by contacting a hydrocarbon slurry of the starting isomers with an epimerization agent selected from the group consisting of 1,1,3,3-tetramethylguanidine and 1,8-diazabicyclo[5.4.0]undec-7-ene, agitating the slurry while maintaining a temperature effective for conversion, and recovering the resulting isomers. The process typically is effective for enriching cypermethrin, and cyfluthrin.
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