122008-78-0

Cyhalofop is a post-emergence herbicide, used mainly for rice as the butyl variant. It is moderately soluble in water and non-volatile. It is not expected to be persistent in the environment. The risk of leaching to groundwater is low. It is moderately toxic to honeybees. It hs a low mammalian oral toxicity.

Cyhalofop is used as a pesticide for controlling pests.

The production of cyhalofop, usually as its active ester form, cyhalofop-butyl, involves a multi-step organic synthesis beginning with the etherification of 3,4-difluorobenzonitrile and hydroquinone under alkaline conditions to yield the key intermediate 4-(4-cyano-2-fluorophenoxy)phenol. This intermediate is then reacted with (S)-2-(4-methylbenzenesulfonyloxy)butyl propionate in the presence of potassium carbonate and a polar aprotic solvent like dimethyl sulfoxide. The reaction promotes nucleophilic substitution, forming the cyhalofop-butyl ester while minimising unwanted double etherification by-products. The final product is purified through standard techniques such as crystallisation or chromatography.

Systemic, foliar untake with no soil activity. Acetyl CoA carboxylase inhibitor (ACCase) - distrupts fatty acid biosynthesis and lipid formation.

Herbicide; Metabolite