摘要 |
Cyhalofop esters are prepared by coupling 2-(4-hydroxyphenoxy)-propionic acid with 3,4-difluorobenzonitrile with base in a polar aprotic solvent (optionally including a phase-transfer catalyst), alkylating with alkyl halide, removing the polar aprotic solvent (optionally using cyhalofop ester as a flux), removing salt by aqueous extraction of molten cyhalofop ester without a solvent, and removing residual water by heating under reduced pressure. |