22898-01-7

Colorless to pale yellow transparent liquid

Moderately toxic by skin contact. Low tox- icity by ingestion.

Flupropanate-sodium is commercially produced via a concise 3–4 step synthesis that begins with the preparation of 2-(4-chloro-2-fluorophenoxy)propanoic acid through nucleophilic aromatic substitution of 4-chloro-2-fluorophenol with ethyl 2-bromopropionate under basic conditions, followed by saponification with sodium hydroxide in aqueous ethanol. The key fluorination is achieved via halogen exchange using potassium fluoride in sulfolane or DMSO at to introduce the 5-fluoro substituent on the phenyl ring (if not pre-fluorinated). Final sodium salt formation occurs by neutralization with sodium hydroxide in water, followed by spray-drying or crystallisation from isopropanol-water to yield flupropanate-sodium.

Systemic, slow acting, absorbed mainly by roots. Inhibition of lipid synthesis.

Herbicide