Process for obtaining an insecticidal product and composites thereof.

摘要

A process is described by which the pair of isomers represented by (R)-a-cyano-4-fluoro-3-phenoxybenzyl (1R,cis)-3-(2,2-dichlorovinyl)-2,2-dimethylcyclopropane carboxylate and its enantiomer is converted by base catalysed epimerisation in solution into the insecticidally more useful isomer pair represented by (S)-a-cyano-4-fluoro-3-phenoxybenzyl (1R,cis)-3-(2,2-dichlorovinyl)-2,2-dimethylcyclopropane carboxylate and its enantiomer, which may then be caused to crystallise out from the solution.