反应详情

There is therefore provided a process for the preparation of gamma-cyhalothrin comprising a) chlorinating 1R cis-Z 3-(2-chloro-3,3,3-trifluoro-1-propenyl)-2,2-dimethyl cyclopropanecarboxylic acid (V) to give 1R cis-Z 3-(2-chloro-3,3,3-trifluoro-1-propenyl)-2,2-dimethyl cyclopropanecarboxylic acid chloride (III); b) esterifying 1R cis-Z 3-(2-chloro-3,3,3-trifluoro-1-propenyl)-2,2-dimethyl cyclopropanecarboxylic acid chloride (III) with 3-phenoxy benzaldehyde (IV) in the presence of a source of cyanide to form a diastereoisomeric mixture of 1R cyhalothrin isomers (II) and c) epimerising the diastereoisomeric mixture (II) under conditions in which the least soluble diastereoisomer (I) crystallises from solution.

1. customThere is therefore provided a process